Glass Compositions, Fiberizable Glass Compositions, and Glass Fibers Made Therefrom

ABSTRACT

The present invention relates generally to glass compositions incorporating rare earth oxides (RE2O3). In one embodiment, a glass composition suitable for fiber forming comprises 51-70 wt. % SiO2, 12.5-22 wt. % Al2O3, 0-20 wt. % CaO, 0-11 wt. % MgO, 0.2-1 wt. % Fe2O3, 0.05 or greater wt. % RE2O3, and greater than 1 wt. % MnOx. In another embodiment, a glass composition suitable for fiber forming comprises 51-70 wt. % SiO2, 12.5-22 wt. % Al2O3, 0-20 wt. % CaO, 0-11 wt. % MgO, 0.2-1 wt. % Fe2O3, 0.05 or greater wt. % RE2O3, 0-4 wt. % BaO, 0-4 wt. % SrO, and 0-5.5 wt. % ZnO, wherein the sum of BaO+SrO+ZnO is greater than about 2 wt. %. In another embodiment, a glass composition suitable for fiber forming comprises 51-70 wt. % SiO2, 12.5-22 wt. % Al2O3, 0-20 wt. % CaO, 0-11 wt. % MgO, 0.2-1 wt. % Fe2O3, 0.05 or greater wt. % RE2O3, and from greater than 0 to 2.5 wt. % Cu2O. In another embodiment, a glass composition suitable for fiber forming comprises 51-70 wt. % SiO2, 12.5-22 wt. % Al2O3, 0-20 wt. % CaO, 0-12.5 wt. % MgO, 0.2-1 wt. % Fe2O3, 0.05 or greater wt. % RE2O3, and at least one additional feature selected from the group consisting of: La2O3 is present in an amount greater than about 2 weight percent, CaO is present in an amount less than about 2 weight percent, a MgO/CaO ratio less than about 1, and a SiO2/Al2O3 ratio greater than about 4. The glass compositions can be used to form glass fibers which can be incorporated into a variety of other fiber glass products (e.g., strands, rovings, fabrics, etc.) and incorporated into various composites.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/019,172, filed on Feb. 9, 2016, which is a continuation ofU.S. patent application Ser. No. 14/325,854, filed on Jul. 8, 2014 andissued as U.S. Pat. No. 9,278,883 on Mar. 8, 2016, which claims priorityto U.S. Provisional Patent Application Ser. No. 61/846,266, filed onJul. 15, 2013, which are all hereby incorporated by reference as thoughfully set forth herein.

FIELD OF THE INVENTION

The present invention relates to glass compositions and, in particular,to glass compositions for forming fibers.

BACKGROUND OF THE INVENTION

Glass fibers have been used to reinforce various polymeric resins formany years. Some commonly used glass compositions for use inreinforcement applications include the “E-glass”, “R-glass”, and“D-glass” families of compositions. “S-glass” is another commonly usedfamily of glass compositions that includes, for example, glass fiberscommercially available from AGY (Aiken, S.C.) under the trade name “S-2Glass.”

In reinforcement and other applications, certain mechanical propertiesof glass fibers or of composites reinforced with glass fibers can beimportant. However, in many instances, the manufacture of glass fibershaving improved mechanical properties (e.g., higher strength, highermodulus, etc.) can result in higher costs due, for example, due toincreased batch material costs, increased manufacturing costs, or otherfactors. For example, the aforementioned “S-2 Glass” has improvedmechanical properties as compared to conventional E-glass but costssignificantly more as well as a result of substantially highertemperature and energy demands for batch-to-glass conversion, meltfining, and fiber drawing. Fiber glass manufacturers continue to seekglass compositions that can be used to form glass fibers havingdesirable mechanical properties in a commercial manufacturingenvironment.

SUMMARY

Various embodiments of the present invention provide glass compositions,fiberizable glass compositions, and glass fibers formed from suchcompositions, as well as fiber glass strands, yarns, fabrics, andcomposites comprising such glass fibers adapted for use in variousapplications.

In one embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and greater than about 1 weight percent MnO_(x). In someembodiments, MnO_(x) comprises MnO₂ in an amount of about 2 weightpercent or greater. In some embodiments, RE₂O₃ comprises at least one ofLa₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at leastabout 1 weight percent in some embodiments. In some embodiments, thecomposition further comprises TiO₂ in an amount greater than about 3weight percent. In some embodiments, the composition further comprisesless than about 1.5 weight percent Na₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, from about 0 to about 4 weight percent BaO, from about 0 to about4 weight percent SrO, and from about 0 to about 5.5 weight percent ZrO,wherein the sum of BaO+SrO+ZnO is greater than about 2 weight percent.In some embodiments, BaO is present in an amount greater than about 2weight percent. In some embodiments, SrO is present in an amount greaterthan about 2 weight percent. In some embodiments, ZnO is present in anamount greater than about 2 weight percent. In some embodiments, RE₂O₃comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ ispresent in an amount of at least about 1 weight percent in someembodiments. In some embodiments, the composition further comprises lessthan about 1.5 weight percent Na₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and from greater than about 0 to about 2.5 weight percent Cu₂O.In some embodiments, the composition comprises 0.5 weight percent orgreater Cu₂O. In some embodiments, RE₂O₃ comprises at least one ofLa₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at leastabout 1 weight percent in some embodiments. In some embodiments, thecomposition further comprises less than about 1.5 weight percentNa₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 12.5 weight percent MgO, from about0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greater weightpercent RE₂O₃, and at least one additional feature selected from thegroup consisting of La₂O₃ is present in an amount greater than about 2weight percent, CaO is present in an amount less than about 2 weightpercent, a MgO/CaO ratio less than about 1, and a SiO₂/Al₂O₃ ratiogreater than about 4. In some embodiments, the additional featurecomprises La₂O₃ in an amount of about 3 weight percent or greater. Insome embodiments, MgO is present in an amount greater than about 6weight percent, and the additional feature comprises CaO in an amountless than about 1.5 weight percent. In some embodiments, the additionalfeature comprises the SiO₂/Al₂O₃ ratio in an amount greater than about4.2. In some embodiments, RE₂O₃ comprises at least one of La₂O₃, Y₂O₃,Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at least about 1weight percent in some embodiments. In some embodiments, the compositionfurther comprises less than about 1.5 weight percent Na₂O+K₂O+Li₂O.

Some embodiments of the present invention relate to fiber glass strands.A number of fiberizable glass compositions are disclosed herein as partof the present invention, and it should be understand that variousembodiments of the present invention can comprise glass fibers, fiberglass strands, yarns, and other products incorporating glass fibersformed from such compositions.

Some embodiments of the present invention relate to yarns formed from atleast one fiber glass strand formed from a glass composition describedherein. Some embodiments of the present invention relate to fabricsincorporating at least one fiber glass strand formed from a glasscomposition described herein. In some embodiments, a fill yarn used inthe fabric can comprise the at least one fiber glass strand. A warpyarn, in some embodiments, can comprise the at least one fiber glassstrand. In some embodiments, fiber glass strands can be used in bothfill yarns and warp yarns used to form fabrics according to the presentinvention. In some embodiments, fabrics of the present invention cancomprise a plain weave fabric, a twill fabric, a crowfoot fabric, asatin weave fabric, a stitch bonded fabric, or a 3D woven fabric.

Some embodiments of the present invention relate to compositescomprising a polymeric resin and glass fibers formed from one of thevarious glass compositions described herein. The glass fibers can befrom a fiber glass strand according to some embodiments of the presentinvention. In some embodiments, the glass fibers can be incorporatedinto a fabric, such as a woven fabric. For example, the glass fibers canbe in a fill yarn and/or a warp yarn that are woven to form a fabric. Inembodiments where the composite comprises a fabric, the fabric cancomprise a plain weave fabric, a twill fabric, a crowfoot fabric, asatin weave fabric, a stitch bonded fabric, or a 3D woven fabric.

The glass fibers can be incorporated into the composite in other formsas well as discussed in more detail below.

With regard to polymeric resins, composites of the present invention cancomprise one or more of a variety of polymeric resins. In someembodiments, the polymeric resin comprises at least one of polyethylene,polypropylene, polyamide, polyimide, polybutylene terephthalate,polycarbonate, thermoplastic polyurethane, phenolic, polyester, vinylester, polydicyclopentadiene, polyphenylene sulfide, polyether etherketone, cyanate esters, bis-maleimides, and thermoset polyurethaneresins. The polymeric resin can comprise an epoxy resin in someembodiments.

Composites of the present invention can be in a variety of forms and canbe used in a variety of applications. Some examples of potential uses ofcomposites according to some embodiments of the present inventioninclude, without limitation, wind energy (e.g., windmill blades),automotive applications, safety/security applications (e.g., ballisticsarmor), aerospace or aviation applications (e.g., interior floors ofplanes), high pressure vessels or tanks, missile casings, electronics,and others.

These and other embodiments of the present invention are described ingreater detail in the Detailed Description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart showing Young's modulus values relative to the amountof rare earth oxides (RE₂O₃) in various glass compositions.

FIG. 2 is a chart showing pristine fiber tensile strength valuesrelative to the amount of rare earth oxides (RE₂O₃) in various glasscompositions.

FIG. 3 is a chart showing softening and glass transition temperaturesrelative to the amount of rare earth oxides (RE₂O₃) in various glasscompositions.

FIG. 4 is a chart showing linear coefficient of thermal expansionrelative to the amount of scandium oxide (Sc₂O₃) in various glasscompositions.

DETAILED DESCRIPTION

Unless indicated to the contrary, the numerical parameters set forth inthe following specification are approximations that can vary dependingupon the desired properties sought to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. Moreover, all ranges disclosed hereinare to be understood to encompass any and all subranges subsumedtherein. For example, a stated range of “1 to 10” should be consideredto include any and all subranges between (and inclusive of) the minimumvalue of 1 and the maximum value of 10; that is, all subranges beginningwith a minimum value of 1 or more, e.g. 1 to 6.1, and ending with amaximum value of 10 or less, e.g., 5.5 to 10. Additionally, anyreference referred to as being “incorporated herein” is to be understoodas being incorporated in its entirety.

It is further noted that, as used in this specification, the singularforms “a,” “an,” and “the” include plural referents unless expressly andunequivocally limited to one referent.

The present invention relates generally to glass compositions. In oneaspect, the present invention provides glass fibers formed from glasscompositions described herein. In some embodiments, glass fibers of thepresent invention can have improved mechanical properties, such as, forexample, Young's modulus and pristine strength, as compared toconventional E-glass fibers.

Glass compositions of the present invention comprise rare earth oxidesin addition to components typically found in glass compositions such asSiO₂, Al₂O₃, CaO, MgO, and others. Such glass compositions can befiberizable and thus can be used to make fiber glass in variousembodiments. As used herein, the term “rare earth oxides” is abbreviatedas “RE₂O₃” and, as understood to those of skill in the art, refers tooxides incorporating a rare earth metal and includes oxides of scandium(Sc₂O₃), yttrium (Y₂O₃), and the lanthanide elements (lanthanum (La₂O₃),cerium (Ce₂O₃ and CeO₂), praseodymium (Pr₂O₃), neodymium (Nd₂O₃),promethium (Pm₂O₃), samarium (Sm₂O₃), europium (Eu₂O₃ and EuO),gadolinium (Gd₂O₃), terbium (Tb₂O₃), dysprosium (Dy₂O₃), holmium(Ho₂O₃), erbium (Er₂O₃), thulium (Tm₂O₃), ytterbium (Yb₂O₃), andlutetium (Lu₂O₃)). The rare earth oxides are included in the glasscompositions of the present invention in amounts that exceed thosewherein the rare earth oxide is present only as a tramp material orimpurity in a batch material included with a glass batch to provideanother component. The glass compositions, in some embodiments, cancomprise a combination of rare earth oxides (e.g., one or more ofvarious rare earth oxides).

In some embodiments, one or more RE₂O₃ can be present in a glasscomposition in an amount of about 0.05 weight percent or greater. Theone or more RE₂O₃ can be present in an amount of about 0.5 weightpercent or greater in some embodiments. The one or more RE₂O₃ can bepresent in an amount of about 1 weight percent or greater in someembodiments. The one or more RE₂O₃ can be present in an amount of about2 weight percent or greater in some embodiments. The one or more RE₂O₃can be present in an amount of about 3 weight percent or greater in someembodiments. The one or more RE₂O₃ can be present in an amount of about4 weight percent or greater in some embodiments. The one or more RE₂O₃can be present in an amount of about 5 weight percent or greater in someembodiments. In some embodiments, the one or more RE₂O₃ can be presentin an amount up to about 10 weight percent although greater amounts canbe used in other embodiments. The one or more RE₂O₃, in someembodiments, can be present in an amount up to about 12 weight percent.The one or more RE₂O₃ can be present in an amount up to about 15 weightpercent in some embodiments. The one or more RE₂O₃, in some embodiments,can be present in an amount from about 0.05 to about 15 weight percent.The one or more RE₂O₃ can be present in an amount from about 0.5 toabout 15 weight percent in some embodiments. In some embodiments, theone or more RE₂O₃ can be present in an amount from about 2.0 to about 15weight percent. The one or more RE₂O₃, in some embodiments, can bepresent in an amount from about 3.0 to about 15 weight percent. In someembodiments, the one or more RE₂O₃ can be present in an amount fromabout 4.0 to about 15 weight percent. The one or more RE₂O₃ can bepresent in an amount from about 5.0 to about 15 weight percent in someembodiments.

The amount of RE₂O₃ used in some embodiments can depend on theparticular RE₂O₃ used, whether other types of RE₂O₃ are used in thecomposition, melt properties of the composition, and desired propertiesof the glass fibers to be formed from the composition, and others.

In some embodiments, RE₂O₃ comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃,and Nd₂O₃. In some embodiments, RE₂O₃ is selected from the groupconsisting of La₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. In some embodiments, RE₂O₃is selected from the group consisting of La₂O₃ and Y₂O₃.

In some embodiments, RE₂O₃ used in glass compositions of the presentinvention can comprise La₂O₃ in an amount of about 0.05 weight percentor greater. In some embodiments, RE₂O₃ can comprise La₂O₃ in an amountof about 0.5 weight percent or greater. In some embodiments, RE₂O₃ cancomprise La₂O₃ in an amount greater than about 2 weight percent. In someembodiments, RE₂O₃ can comprise La₂O₃ in an amount of about 3 weightpercent or greater. In some embodiments, RE₂O₃ can comprise La₂O₃ in anamount from greater than about 2 weight percent to about 21 weightpercent. In some embodiments, RE₂O₃ can comprise La₂O₃ in an amount fromgreater than about 2 weight percent to about 10 weight percent. In someembodiments, RE₂O₃ can comprise La₂O₃ in an amount from greater thanabout 2 weight percent to about 6 weight percent. In some embodiments,RE₂O₃ can comprise La₂O₃ in an amount from about 3 weight percent toabout 10 weight percent. In some embodiments, RE₂O₃ can comprise La₂O₃in an amount from about 3 weight percent to about 6 weight percent. Insome embodiments, the glass composition can be substantially free ofLa₂O₃. As set forth above and in the Examples below, other amounts ofLa₂O₃ can also be included in glass compositions according to someembodiments. In some embodiments, the inclusion of La₂O₃ in glasscompositions is believed to have a desirable impact on glass softeningtemperature and glass transition temperatures as well as on tensilestrength, elongation, coefficient of thermal expansion, and otherproperties of glass fibers formed from the compositions.

In some embodiments, the RE₂O₃ used in glass compositions of the presentinvention can comprise Y₂O₃ in an amount of about 0.05 weight percent orgreater. In some embodiments, RE₂O₃ can comprise Y₂O₃ in an amount ofabout 0.5 weight percent or greater. In some embodiments, Y₂O₃ can bepresent in an amount from about 0.05 to about 15 weight percent. In someembodiments, Y₂O₃ can be present in an amount up to about 6 weightpercent. In some embodiments, Y₂O₃ can be present in an amount fromabout 3 to about 5.5 weight percent. In some embodiments, the Y₂O₃content can be about 2 weight percent or less. In some embodiments, theglass composition can be substantially free of Y₂O₃. As set forth aboveand in the Examples below, other amounts of Y₂O₃ can also be included inglass compositions according to some embodiments. In some embodiments,the inclusion of Y₂O₃ in glass compositions is believed to have adesirable impact on glass softening temperature and glass transitiontemperature as well as on modulus, tensile strength, elongation,coefficient of thermal expansion, and other properties of glass fibersformed from the compositions.

In some embodiments, the RE₂O₃ used in glass compositions of the presentinvention can comprise Sc₂O₃ in an amount of about 0.05 weight percentor greater. In some embodiments, RE₂O₃ can comprise Sc₂O₃ in an amountof about 0.5 weight percent or greater. In some embodiments, Sc₂O₃ canbe present in an amount from about 0.5 to about 4 weight percent. Insome embodiments, the glass composition can be substantially free ofSc₂O₃. As set forth above and in the Examples below, other amounts ofSc₂O₃ can also be included in glass compositions according to someembodiments. In some embodiments, while the inclusion of Sc₂O₃ in glasscompositions is believed to have a desirable impact on some propertiesof glass fibers formed from the compositions (e.g., glass softeningtemperature, glass transition temperature, coefficient of thermalexpansion, etc.), the presence of Sc₂O₃ has also been observed to raisethe liquidus temperature of the compositions.

In some embodiments, the RE₂O₃ used in glass compositions of the presentinvention can comprise Nd₂O₃ in an amount of about 0.05 weight percentor greater. In some embodiments, RE₂O₃ can comprise Sc₂O₃ in an amountof about 0.5 weight percent or greater. In some embodiments, Nd₂O₃ canbe present in an amount from about 0.5 to about 15 weight percent. Insome embodiments, the glass composition can be substantially free ofNd₂O₃. As set forth above and in the Examples below, other amounts ofNd₂O₃ can also be included in glass compositions according to someembodiments. In some embodiments, the inclusion of Nd₂O₃ in glasscompositions is believed to have a desirable impact on glass softeningtemperature and glass transition temperature as well as on modulus,tensile strength, elongation, coefficient of thermal expansion, andother properties of glass fibers formed from the compositions.

Various combinations of RE₂O₃ can be also used to achieve desirableproperties (e.g., tensile strength, modulus, specific strength, specificmodulus, etc.). For example, the selection of a particular RE₂O₃ and itsrelative amount can impact the fiber density which can in turn impactspecific strength (tensile strength divided by density) and specificmodulus (modulus divided by density). Likewise, the selection of aparticular RE₂O₃ and its relative amount can impact melt properties ofthe glass compositions. For example, as noted above, the presence ofSc₂O₃ in certain amounts can increase the liquidus temperature of aglass composition. Similarly, cerium oxide (Ce₂O₃ and CeO₂) can act asan oxidizing and fining agent, such that in some embodiments, the amountof cerium oxide can be no more than 2 weight percent. In someembodiments, the glass composition can be substantially free of ceriumoxide. Finally, the selection of a particular RE₂O₃ and its relativeamount can impact the cost of making the glass fibers due to its impacton melt properties and due its cost as a raw material as the cost ofRE₂O₃ varies substantially.

As noted above, glass compositions of the present invention and inparticular, fiberizable glass compositions also include other componentsincluding SiO₂, Al₂O₃, CaO, MgO, and others.

In one embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and greater than about 1 weight percent MnO_(x). In someembodiments, MnO_(x) comprises MnO₂ in an amount of about 2 weightpercent or greater. In some embodiments, RE₂O₃ comprises at least one ofLa₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at leastabout 1 weight percent in some embodiments. In some embodiments, thecomposition further comprises TiO₂ in an amount greater than about 3weight percent. In some embodiments, the composition further comprisesless than about 1.5 weight percent Na₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, from about 0 to about 4 weight percent BaO, from about 0 to about4 weight percent SrO, and from about 0 to about 5.5 weight percent ZrO,wherein the sum of BaO+SrO+ZnO is greater than about 2 weight percent.In some embodiments, BaO is present in an amount greater than about 2weight percent. In some embodiments, SrO is present in an amount greaterthan about 2 weight percent. In some embodiments, ZnO is present in anamount greater than about 2 weight percent. In some embodiments, RE₂O₃comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ ispresent in an amount of at least about 1 weight percent in someembodiments. In some embodiments, the composition further comprises lessthan about 1.5 weight percent Na₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and from greater than about 0 to about 2.5 weight percent Cu₂O.In some embodiments, the composition comprises 0.5 weight percent orgreater Cu₂O. In some embodiments, RE₂O₃ comprises at least one ofLa₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at leastabout 1 weight percent in some embodiments. In some embodiments, thecomposition further comprises less than about 1.5 weight percentNa₂O+K₂O+Li₂O.

In another embodiment, a glass composition suitable for fiber formingcomprises from about 51 to about 70 weight percent SiO₂, from about 12.5to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 12.5 weight percent MgO, from about0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greater weightpercent RE₂O₃, and at least one additional feature selected from thegroup consisting of La₂O₃ is present in an amount greater than about 2weight percent, CaO is present in an amount less than about 2 weightpercent, a MgO/CaO ratio less than about 1, and a SiO₂/Al₂O₃ ratiogreater than about 4. In some embodiments, La₂O₃ is present in an amountof about 3 weight percent or greater. In some embodiments, CaO ispresent in an amount less than about 1.5 weight percent and MgO ispresent in an amount greater than about 6 weight percent. In someembodiments, the SiO₂/Al₂O₃ ratio is greater than about 4.2. In someembodiments, RE₂O₃ comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃, andNd₂O₃. RE₂O₃ is present in an amount of at least about 1 weight percentin some embodiments. In some embodiments, the composition furthercomprises less than about 1.5 weight percent Na₂O+K₂O+Li₂O.

It should be understood that any component of a glass compositiondescribed as being present in amount from about 0 weight percent toanother weight percent is not necessarily required in all embodiments.In other words, such components may be optional in some embodiments,depending of course on the amounts of other components included in thecompositions. Likewise, in some embodiments, glass compositions can besubstantially free of such components, meaning that any amount of thecomponent present in the glass composition would result from thecomponent being present as a trace impurity in a batch material. Acomponent present as a trace impurity is not intentionally added to theglass composition. In other words, a trace impurity is present in aherein described glass composition by virtue of its presence as animpurity in a starting material added to the glass composition.Generally, a trace impurity is present in the glass composition in anamount no greater than about 0.1 weight percent, although some traceimpurities may be present in the glass composition in an amount up toabout 0.5 weight percent.

Some embodiments of the present invention can be characterized by theamount of SiO₂ present in the glass compositions. SiO₂ can be present inan amount from about 51 to about 70 weight percent in some embodiments.SiO₂ can be present in an amount from about 51 to about 66 weightpercent in some embodiments. The SiO₂ content in some embodiments can beless than about 66 weight percent. SiO₂ can be present in an amount fromabout 51 to about 65 weight percent, and from about 51 to about 63weight percent in some embodiments. SiO₂ can be present, in someembodiments, in an amount from about 54 to about 65 weight percent andfrom about 54 to about 63 weight percent. In some embodiments, SiO₂ canbe present in an amount from about 58 to about 66 weight percent. Insome embodiments, SiO₂ can be present in an amount from about 58 toabout 64 weight percent. In some embodiments, SiO₂ can be present in anamount from about 59 to about 65 weight percent. In some embodiments,SiO₂ can be present in an amount from about 58 to about 70 weightpercent. In some embodiments, SiO₂ can be present in an amount fromabout 65 to about 70 weight percent. The glass compositions, in someembodiments, can comprise at least about 60 weight percent SiO₂.

Some embodiments of the present invention can be characterized by theamount of Al₂O₃ present in the glass compositions. In some embodiments,glass compositions can comprise from about 12.5 to about 22 weightpercent Al₂O₃. Al₂O₃ can be present, in some embodiments, in an amountfrom about 12.5 to about 19 weight percent. Al₂O₃ can be present in anamount from about 13 to about 22 weight percent in some embodiments.Al₂O₃ can be present in an amount from about 14.5 to about 19 weightpercent in some embodiments. In some embodiments, Al₂O₃ can be presentin an amount from about 15 to about 19 weight percent. In someembodiments, Al₂O₃ can be present in an amount from about 15 to about 18weight percent.

Some embodiments of the present invention can be characterized by theratio of SiO₂ content to Al₂O₃ content (SiO₂/Al₂O₃). The SiO₂/Al₂O₃ratio can affect the Young's modulus of the glass compositions. In someembodiments, the SiO₂/Al₂O₃ ratio is about 2 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 3 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 3.5 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 3.8 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 4 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 4.2 or greater. In someembodiments, the SiO₂/Al₂O₃ ratio is about 4.5 or greater.

Some embodiments of the present invention can be characterized by theamount of CaO present in the glass compositions. CaO can be present inan amount from about 0 to about 20 weight percent in some embodiments.CaO can be present, in some embodiments, in an amount from about 0 andto 16 weight percent. In some embodiments, the CaO content can be lessthan 10 weight percent. In some embodiments, the CaO content can be lessthan 8 weight percent. In some embodiments, the CaO content can be lessthan 2 weight percent. In some embodiments, the CaO content can be 1.5weight percent or less. In some embodiments, the CaO content can be 1weight percent or less. In some embodiments, CaO can be present in anamount from about 10 to about 20 weight percent. In some embodiments,CaO can be present in an amount from about 12 to about 20 weightpercent. In some embodiments, CaO can be present in an amount from about15 to about 20 weight percent. In some embodiments, CaO can be presentin an amount from about 0.5 to about 15 weight percent. Glasscompositions of the present invention, in some embodiments, can comprisefrom about 0.5 to about 14 weight percent. In some embodiments, CaO canbe present in an amount from about 0.5 to about 10 weight percent. Insome embodiments, CaO can be present in an amount from about 2 to about8 weight percent. In some embodiments, the glass composition can besubstantially free of CaO.

Some embodiments of the present invention can be characterized by theamount of MgO present in the glass compositions. MgO can be present inan amount from about 0 to about 12.5 weight percent in some embodiments.In some embodiments, glass compositions of the present inventioncomprise from about 0 to about 12 weight percent MgO. MgO can be presentin an amount from about 0 to about 11 weight percent in someembodiments. MgO can be present in an amount from greater than about 0to about 11 weight percent in some embodiments. MgO can be present in anamount from about 1 to about 11 weight percent in some embodiments. MgOcan be present in an amount from greater than about 0 to about 9 weightpercent in some embodiments. MgO can be present in an amount of about 6weight percent or greater in some embodiments. MgO can be present in anamount of about 6.5 weight percent or greater in some embodiments. MgOcan be present, in some embodiments, in an amount from about 6.5 toabout 12.5 weight percent. MgO can be present, in some embodiments, inan amount from about 7 to about 12.5 weight percent. MgO can be present,in some embodiments, in an amount from about 6 to about 9 weightpercent. In some embodiments, the glass composition can be substantiallyfree of MgO.

Some embodiments of the present invention can be characterized by theratio of MgO content to CaO content (MgO/CaO). The MgO/CaO ratio mayaffect the Young's modulus and the liquidus temperature of the glasscomposition. In some embodiments in which MgO and CaO are present, theMgO/CaO ratio may be less than about 1. In some embodiments, the MgO/CaOratio can be less than about 0.8. In some embodiments, the MgO/CaO ratiocan be less than about 0.6. In some embodiments, the MgO/CaO ratio canbe greater than about 4. In some embodiments, the MgO/CaO ratio can begreater than about 4.5 In some embodiments, the MgO/CaO ratio can begreater than about 5. In some embodiments, the MgO/CaO ratio can begreater than about 10.

Some embodiments of the present invention can be characterized by theamount of BaO present in the glass compositions. In some embodiments,BaO can be present in an amount greater than 0 weight percent, 0.5weight percent or greater, 1 weight percent or greater, 2 weight percentor greater, or 3 weight percent or greater. BaO can be present in anamount from about 0 to about 4 weight percent in some embodiments. Insome embodiments, glass compositions of the present invention comprisefrom about 0 to about 3.5 weight percent BaO. BaO can be present in anamount from greater than about 0 to about 4 weight percent in someembodiments. BaO can be present in an amount from about 0.5 to about 4weight percent in some embodiments. BaO can be present in an amount fromabout 1 to about 4 weight percent in some embodiments. BaO can bepresent in an amount from about 2 to about 4 weight percent in someembodiments. BaO can be present in an amount from about 2.5 to about 4weight percent in some embodiments. BaO can be present in an amount fromabout 3 to about 4 weight percent in some embodiments. In someembodiments, the glass composition can be substantially free of BaO.

Some embodiments of the present invention can be characterized by theamount of SrO present in the glass compositions. In some embodiments,SrO can be present in an amount greater than 0 weight percent, 0.5weight percent or greater, 1 weight percent or greater, 2 weight percentor greater, or 3 weight percent or greater. SrO can be present in anamount from about 0 to about 4 weight percent in some embodiments. Insome embodiments, glass compositions of the present invention comprisefrom about 0 to about 3.5 weight percent SrO. SrO can be present in anamount from greater than about 0 to about 4 weight percent in someembodiments. SrO can be present in an amount from about 0.5 to about 4weight percent in some embodiments. SrO can be present in an amount fromabout 1 to about 4 weight percent in some embodiments. SrO can bepresent in an amount from about 2 to about 4 weight percent in someembodiments. SrO can be present in an amount from about 2.5 to about 4weight percent in some embodiments. In some embodiments, the glasscomposition can be substantially free of SrO.

Some embodiments of the present invention can be characterized by thetotal amount of CaO, MgO, BaO, and SrO content (CaO+MgO+BaO+SrO). TheCaO+MgO+BaO+SrO content can be 23 weight percent or less in someembodiments. The CaO+MgO+BaO+SrO content can be from about 1 to about 23weight percent. The CaO+MgO+BaO+SrO content can be from about 8 to about23 weight percent. The CaO+MgO+BaO+SrO content can be from about 9 toabout 23 weight percent. The CaO+MgO+BaO+SrO content can be from about 9to about 20 weight percent. The CaO+MgO+BaO+SrO content can be fromabout 9 to about 17 weight percent. The CaO+MgO+BaO+SrO content can befrom about 0 to about 8 weight percent. The CaO+MgO+BaO+SrO content canbe from about 1 to about 8 weight percent. The CaO+MgO+BaO+SrO contentcan be from about 1 to about 6 weight percent. The CaO+MgO+BaO+SrOcontent can be from about 1 to about 3 weight percent.

Some embodiments of the present invention can be characterized by theamount of ZnO present in the glass compositions. In some embodiments,ZrO can be present in an amount greater than 0 weight percent, 0.5weight percent or greater, 1 weight percent or greater, 2 weight percentor greater, or 3 weight percent or greater. ZnO can be present in anamount from about 0 to about 5.5 weight percent in some embodiments. Insome embodiments, glass compositions of the present invention comprisefrom about 0 to about 5 weight percent ZnO. ZnO can be present in anamount from greater than about 0 to about 5.5 weight percent in someembodiments. ZnO can be present in an amount from greater than about 0to about 5 weight percent in some embodiments. ZnO can be present in anamount from about 1 to about 5 weight percent in some embodiments. ZnOcan be present in an amount from about 1.5 to about 5 weight percent insome embodiments. ZnO can be present in an amount from about 2 to about5 weight percent in some embodiments. ZnO can be present in an amountfrom about 2.5 to about 5 weight percent in some embodiments. ZnO can bepresent in an amount from about 4 to about 5 weight percent in someembodiments. In some embodiments, the glass composition can besubstantially free of ZnO.

Some embodiments of the present invention can be characterized by thetotal amount of BaO, SrO, and ZnO content (BaO+SrO+ZnO). The BaO+SrO+ZnOcontent can be greater than 1 weight percent in some embodiments. TheBaO+SrO+ZnO content can be 2 weight percent or greater in someembodiments. The BaO+SrO+ZnO content can be 2.5 weight percent orgreater in some embodiments. The BaO+SrO+ZnO content can be 3 weightpercent or greater in some embodiments. The BaO+SrO+ZnO content can beup to 10 weight percent in some embodiments. The BaO+SrO+ZnO content canbe up to 6 weight percent in some embodiments. The BaO+SrO+ZnO contentcan be up to 5.5 weight percent in some embodiments. The BaO+SrO+ZnOcontent can be up to 5 weight percent in some embodiments. TheBaO+SrO+ZnO content can be from 2 to 6 weight percent in someembodiments. The BaO+SrO+ZnO content can be from 2.5 to 5 weight percentin some embodiments. In some embodiments, the glass composition can besubstantially free of any one of BaO, SrO, and ZnO. In some embodiments,the glass composition can be substantially free of any combination ofBaO, SrO, and ZnO, including being substantially free of all of BaO,SrO, and ZnO.

Some embodiments of the present invention can be characterized by theamount of Na₂O present in the glass compositions. In some embodiments,glass compositions of the present invention can comprise from about 0 toabout 2.5 weight percent Na₂O. Na₂O can be present, in some embodiments,in an amount from about 0 to about 1.5 weight percent. Na₂O can bepresent, in some embodiments, in an amount from about 0 to about 1weight percent. In some embodiments, Na₂O can be present in an amount upto about 1.5 weight percent. Na₂O can be present, in some embodiments,in an amount up to about 1.0 weight percent. Na₂O can be present, insome embodiments, in an amount up to about 0.5 weight percent. Na₂O canbe present, in some embodiments, in an amount up to about 0.25 weightpercent. Na₂O can be present, in some embodiments, in an amount up toabout 0.1 weight percent. In some embodiments, the glass composition canbe substantially free of Na₂O.

Some embodiments of the present invention can be characterized by theamount of K₂O present in the glass compositions. K₂O can be present, insome embodiments, in an amount from about 0 to about 1 weight percent.In some embodiments, K₂O can be present in an amount up to about 1weight percent. K₂O can be present, in some embodiments, in an amount upto about 0.5 weight percent. K₂O can be present, in some embodiments, inan amount up to about 0.3 weight percent. K₂O can be present, in someembodiments, in an amount up to about 0.1 weight percent. In someembodiments, the glass composition can be substantially free of K₂O.

Some embodiments of the present invention can be characterized by theamount of Li₂O present in the glass compositions. In some embodiments,glass compositions of the present invention can comprise from about 0 toabout 2 weight percent Li₂O. Li₂O can be present, in some embodiments,in an amount from about 0 to about 1 weight percent. In someembodiments, Li₂O can be present from greater than about 0 to about 1weight percent. Li₂O can be present, in some embodiments, in an amountfrom about 0.4 to about 2 weight percent. Li₂O can be present, in someembodiments, in an amount from about 0.4 to about 1 weight percent. Li₂Ocan be present, in some embodiments, in an amount from about 0.5 toabout 1 weight percent. In some embodiments, the glass composition canbe substantially free of Li₂O.

Some embodiments of the present invention can be characterized by thetotal amount of Na₂O, K₂O, and Li₂O content (Na₂O+K₂O+Li₂O). In someembodiments, the Na₂O+K₂O+Li₂O content in glass compositions of thepresent invention is greater than about 1 weight percent. TheNa₂O+K₂O+Li₂O content, in some embodiments, is up to about 2.5 weightpercent. In some embodiments, the Na₂O+K₂O+Li₂O content is present in anamount greater than about 1 weight percent and up to about 2.5 weightpercent. In some embodiments, the Na₂O+K₂O+Li₂O content in glasscompositions of the present invention is from about 0 to about 1.5weight percent. In some embodiments, the Na₂O+K₂O+Li₂O content in glasscompositions of the present invention is from about 0 to about 1.0weight percent. In some embodiments, the Na₂O+K₂O+Li₂O content in glasscompositions of the present invention is from about 0 to about 0.8weight percent. In some embodiments, the Na₂O+K₂O+Li₂O content in glasscompositions of the present invention is from about 0 to about 0.6weight percent.

Some embodiments of the present invention can be characterized by theamount of Cu₂O present in the glass compositions. Cu₂O can be present,in some embodiments, in an amount from about 0 to about 2.5 weightpercent. Cu₂O can be present, in some embodiments, in an amount fromabout 0 to about 2 weight percent. Cu₂O can be present, in someembodiments, in an amount from about 0 to about 1.7 weight percent. Cu₂Ocan be present, in some embodiments, in an amount from greater thanabout 0 to about 2.5 weight percent. Cu₂O can be present, in someembodiments, in an amount from greater than about 0 to about 2 weightpercent. Cu₂O can be present, in some embodiments, in an amount fromgreater than about 0 to about 1.7 weight percent. Cu₂O can be present,in some embodiments, in an amount of 0.5 weight percent or greater. Cu₂Ocan be present, in some embodiments, in an amount from about 0.5 toabout 2.5 weight percent. Cu₂O can be present, in some embodiments, inan amount from about 0.5 to about 2 weight percent. Cu₂O can be present,in some embodiments, in an amount from about 0.5 to about 1.7 weightpercent. In some embodiments, the glass composition can be substantiallyfree of Cu₂O.

Some embodiments of the present invention can be characterized by theamount of B₂O₃ present in the glass compositions. B₂O₃ can be present inan amount from about 0 to about 3 weight percent in some embodiments. Insome embodiments, B₂O₃ can be present in an amount from about 0 to about2 weight percent or from about 0 to less than about 2 weight percent.B₂O₃ can be present, in some embodiments, in an amount from about 0 toabout 1.5 weight percent. In some embodiments, the B₂O₃ content can beabout 1 weight percent or less. In some embodiments, the B₂O₃ contentcan be about 0.5 weight percent or less. In some embodiments, glasscompositions of the present invention can be substantially free of B₂O₃.In other embodiments, glass compositions of the present invention cancomprise greater than about 1 weigh percent B₂O₃. In some embodiments,B₂O₃ can be present in an amount from greater than about 0 to about 10weight percent.

Some embodiments of the present invention can be characterized by theamount of Fe₂O₃ present in the glass compositions. In some embodiments,Fe₂O₃ can be present in an amount from about 0 to about 1.0 weightpercent. In some embodiments, Fe₂O₃ can be about 0.5 weight percent orless. In some embodiments, Fe₂O₃ can be present in an amount fromgreater than about 0 to about 1.0 weight percent. Fe₂O₃ can be present,in some embodiments, in an amount from greater than about 0 to about 0.5weight percent. In some embodiments, Fe₂O₃ can be present in an amountfrom greater than about 0 to about 0.4 weight percent. Fe₂O₃ can bepresent, in some embodiments, from about 0.1 to about 1.0 weightpercent. Fe₂O₃ can be present, in some embodiments, from about 0.2 toabout 1.0 weight percent. Fe₂O₃ can be present, in some embodiments,from about 0.25 to about 1.0 weight percent. Fe₂O₃ can be present, insome embodiments, from about 0.3 to about 1.0 weight percent. Fe₂O₃ canbe present, in some embodiments, from about 0.2 to about 0.8 weightpercent, or from about 0.2 to about 0.5 weight percent. Fe₂O₃ can bepresent, in some embodiments, from about 0.25 to about 0.8 weightpercent, or from about 0.25 to about 0.5 weight percent. Fe₂O₃ can bepresent, in some embodiments, from about 0.3 to about 0.8 weightpercent, or from about 0.3 to about 0.5 weight percent.

Some embodiments of the present invention can be characterized by theamount of TiO₂ present in the glass compositions. TiO₂ can be present,in some embodiments, in an amount greater than 0 weight percent, 1.5weight percent or greater, 3 weight percent or greater, 4 weight percentor greater, or 5 weight percent or greater. TiO₂ can be present, in someembodiments, in an amount from about 0 to about 9 weight percent. TiO₂can be present, in some embodiments, in an amount from greater thanabout 1.5 to about 9 weight percent. TiO₂ can be present, in someembodiments, in an amount from greater than about 3 to about 9 weightpercent. TiO₂ can be present, in some embodiments, in an amount fromgreater than about 4 to about 9 weight percent. TiO₂ can be present, insome embodiments, in an amount from about 5 to about 9 weight percent.TiO₂ can be present, in some embodiments, in an amount from about 0 toabout 3 weight percent. TiO₂ can be present, in some embodiments, in anamount from about 0 to about 2 weight percent. TiO₂ can be present, insome embodiments, in an amount from about 0 to about 1 weight percent.In some embodiments, TiO₂ can be present in an amount from greater than0 to about 3 weight percent. In some embodiments, the glass compositioncan be substantially free of TiO₂.

Some embodiments of the present invention can be characterized by theamount of ZrO₂ present in the glass compositions. ZrO₂ can be present,in some embodiments, in an amount from about 0 to about 3 weightpercent. In some embodiments, ZrO₂ can be present in an amount up toabout 2 weight percent. In some embodiments, glass compositions of thepresent invention can be substantially free of ZrO₂.

Some embodiments of the present invention can be characterized by theamount of MnO_(x) present in the glass compositions. As used herein, theterm MnO_(x) refers to the genus consisting of MnO and MnO₂. As usedthroughout, a range of MnO_(x) can include any amount of MnO and MnO₂which, in sum, are within the range of MnO_(x). By way of example, arange from about 0 to about 9.5 MnO_(x) can include (i) about 0 weightpercent MnO and about 9.5 weight percent MnO₂, (ii) about 9.5 weightpercent MnO and about 0 weight percent MnO₂, or (iii) any weight percentcombination of MnO and MnO_(x) within the range from about 0 to about9.5 weight percent. MnO_(x) can be present, in some embodiments, in anamount of about 1 weight percent or greater, about 1.5 weight percent orgreater, about 2 weight percent or greater, about 3 weight percent orgreater, or about 4 weight percent or greater. MnO_(x) can be present,in some embodiments, in an amount from about 0 to about 9.5 weightpercent. MnO_(x) can be present, in some embodiments, in an amount fromgreater than about 0 to about 9.5 weight percent. MnO_(x) can bepresent, in some embodiments, in an amount from about 1 to about 9.5weight percent. MnO_(x) can be present, in some embodiments, in anamount from about 1.5 to about 9.5 weight percent. MnO_(x) can bepresent, in some embodiments, in an amount from about 2 to about 9.5weight percent. MnO_(x) can be present, in some embodiments, in anamount from about 4 to about 9.5 weight percent. In some embodiments inwhich MnO is present, MnO can be present in an amount greater than about2 weight percent. Thus, the MnO_(x) content can be greater than about 1weight percent, wherein if MnO is present, then MnO is present an amountof about 2 weight percent or greater. In some embodiments, MnO_(x)consists essentially of MnO in an amount from about 0 to about 8.5weight percent. In some embodiments, MnO_(x) consists essentially of MnOin an amount from about 1.5 to about 8.5 weight percent. In someembodiments, MnO_(x) consists essentially of MnO in an amount from about2 to about 8 weight percent. In some embodiments, MnO_(x) consistsessentially of MnO₂ in an amount from about 0 to about 9.5 weightpercent. In some embodiments, MnO_(x) consists essentially of MnO₂ in anamount from about 1.5 to about 9.5 weight percent. In some embodiments,MnO_(x) consists essentially of MnO₂ in an amount from about 4 to about9.5 weight percent. In some embodiments, glass compositions of thepresent invention can be substantially free of MnO, MnO₂, or MnO_(x).

Some embodiments of the present invention can be characterized by theamount of P₂O₅ present in the glass compositions. P₂O₅ can be present,in some embodiments, in an amount from about 0 to about 3 weightpercent. In some embodiments, P₂O₅ can be present in an amount up toabout 2.5 weight percent. In some embodiments, glass compositions of thepresent invention can be substantially free of P₂O₅.

Sulfate (expressed as SO₃) may also be present as a refining agent.Small amounts of impurities may also be present from raw materials orfrom contamination during the melting processes, such as Cl₂, Cr₂O₃, orNiO (not limited to these particular chemical forms). Other refiningagents and/or processing aids may also be present such as As₂O₃, Sb₂O₃,SnO₂ or CeO₂ (not limited to these particular chemical forms). Theseimpurities and refining agents, when present, are each typically presentin amounts less than about 0.5% by weight of the total glasscomposition. In some embodiments, the glass composition can besubstantially free of any one of these refining agents, or can besubstantially free of any combination of these refining agents.

Some embodiments of the present invention can be characterized by thepresence of an additional feature in the glass compositions. Theadditional feature is not particularly limited. The additional featurecan comprise any one or more compound(s), component(s), and/or ratio(s)in any amount(s) or range(s) disclosed herein. In some embodiments, theadditional feature can comprise La₂O₃ in an amount greater than about 2weight percent. In some embodiments, the additional feature can compriseCaO in an amount less than about 2 weight percent. In some embodiments,the additional feature can comprise a MgO/CaO ratio less than about 1.In some embodiments, the additional feature can comprise a SiO₂/Al₂O₃ratio greater than about 4.

As noted above, glass compositions, according to some embodiments of thepresent invention are fiberizable. In some embodiments, glasscompositions of the present invention have forming temperatures (T_(F))desirable for use in commercial fiber glass manufacturing operations. Asused herein, the term “forming temperature” or T_(F), means thetemperature at which the glass composition has a viscosity of 1000 poise(or “log 3 temperature”). Glass compositions of the present invention,in some embodiments, have a forming temperature (T_(F)) ranging fromabout 1250° C. to about 1550° C. In another embodiment, glasscompositions of the present invention have a forming temperature rangingfrom about 1250° C. to about 1415° C. In another embodiment, glasscompositions of the present invention have a forming temperature rangingfrom about 1250° C. to about 1350° C. In some embodiments, glasscompositions have a forming temperature ranging from about 1250° C. toabout 1310° C.

Glass compositions of the present invention, in some embodiments, have aliquidus temperature ranging from about 1150° C. to about 1515° C. Inanother embodiment, glass compositions of the present invention have aliquidus temperature ranging from about 1190° C. to about 1515° C. Inanother embodiment, glass compositions of the present invention have aliquidus temperature ranging from about 1190° C. to about 1300° C. Insome embodiments, glass compositions of the present invention have aliquidus temperature ranging from about 1190° C. to about 1260° C.

In some embodiments, the difference between the forming temperature andthe liquidus temperature of a glass composition of the present inventionis desirable for commercial fiber glass manufacturing operations. Forexample, for some embodiments of glass compositions, the differencebetween the forming temperature and the liquidus temperature ranges fromabout 25° C. to greater than 60° C. In some embodiments, the differencebetween the forming temperature and the liquidus temperature of a glasscomposition of the present invention ranges from about 35° C. to greaterthan 60° C. In some embodiments, the difference between the formingtemperature and the liquidus temperature of a glass composition of thepresent invention is at least 50° C. In some embodiments, the differencebetween the forming temperature and the liquidus temperature of a glasscomposition of the present invention is up to 200° C.

As provided herein, glass fibers can be formed from some embodiments ofthe glass compositions of the present invention. Thus, embodiments ofthe present invention can comprise glass fibers formed from any of theglass compositions described herein. In some embodiments, the glassfibers may be arranged into a fabric. In some embodiments, glass fibersof the present invention can be provided in other forms including, forexample and without limitation, as continuous strands, chopped strands(dry or wet), yarns, rovings, prepregs, etc. In short, variousembodiments of the glass compositions (and any fibers formed therefrom)can be used in a variety of applications.

Some embodiments of the present invention relate to fiber glass strands.Some embodiments of the present invention relate to yarns comprisingfiber glass strands. Some embodiments of yarns of the present inventionare particularly suitable for weaving applications. In addition, someembodiments of the present invention relate to glass fiber fabrics. Someembodiments of fiber glass fabrics of the present invention areparticularly suitable for use in reinforcement applications, especiallyreinforcement applications in which high modulus, high strength, and/orhigh elongation are important. Further, some embodiments of the presentinvention relate to composites that incorporate fiber glass strands,fiber glass yarns, and fiber glass fabrics, such as fiber reinforcedpolymer composites. Some composites of the present invention areparticularly suitable for use in reinforcement applications, especiallyreinforcement applications in which high modulus, high strength, and/orhigh elongation are important, such as wind energy (e.g., windmillblades), automotive applications, safety/security applications (e.g.,ballistics armor or armor panels), aerospace or aviation applications(e.g., interior floors of planes), high pressure vessels or tanks,missile casings, and others. Some embodiments of the present inventionrelate to automotive composites. Some embodiments of the presentinvention relate to aerospace composites. Other embodiments of thepresent application relate to aviation composites. Still otherembodiments of the present invention relate to composites suitable foruse in wind energy applications. Some embodiments of the presentinvention relate to prepregs. Some embodiments of the present inventionrelate to composites for safety/security applications such as armorpanels. Other embodiments of the present invention relate to compositesfor high pressure vessels or storage tanks. Some embodiments of thepresent invention relate to composites for missile casings. Otherembodiments of the present invention relate to composites for use inhigh temperature thermal insulation applications. Some embodiments ofthe present invention relate to printed circuit boards where lowercoefficients of thermal expansion are particularly desirable such assubstrates for chip packaging.

Some embodiments of the present invention relate to fiber glass strands.In some embodiments, a fiber glass strand of the present inventioncomprises a plurality of glass fibers comprising a glass compositionthat comprises the following components:

SiO₂ from about 51 to about 70 weight percent; Al₂O₃ from about 12.5 toabout 22 weight percent; CaO from about 0 to about 20 weight percent;MgO from about 0 to about 11 weight percent; Fe₂O₃ from about 0.2 toabout 1 weight percent; RE₂O₃ about 0.05 or greater weight percent; andMnO_(x) greater than about 1 weight percent.

In some embodiments, MnO_(x) comprises MnO₂ in an amount of about 2weight percent or greater. In some embodiments, RE₂O₃ comprises at leastone of La₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount ofat least about 1 weight percent in some embodiments. In someembodiments, the composition further comprises TiO₂ in an amount greaterthan about 3 weight percent. In some embodiments, the compositionfurther comprises less than about 1.5 weight percent Na₂O+K₂O+Li₂O.

In some embodiments, a fiber glass strand of the present inventioncomprises a plurality of glass fibers comprising a glass compositionthat comprises the following components:

SiO₂ from about 51 to about 70 weight percent; Al₂O₃ from about 12.5 toabout 22 weight percent; CaO from about 0 to about 20 weight percent;MgO from about 0 to about 11 weight percent; Fe₂O₃ from about 0.2 toabout 1 weight percent; RE₂O₃ about 0.05 or greater weight percent; BaOfrom about 0 to about 4 weight percent; SrO from about 0 to about 4weight percent; and ZnO from about 0 to about 5.5 weight percent;

wherein the sum of BaO+SrO+ZnO is greater than about 2 weight percent.

In some embodiments, BaO is present in an amount greater than about 2weight percent. In some embodiments, SrO is present in an amount greaterthan about 2 weight percent. In some embodiments, ZnO is present in anamount greater than about 2 weight percent. In some embodiments, RE₂O₃comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ ispresent in an amount of at least about 1 weight percent in someembodiments. In some embodiments, the composition further comprises lessthan about 1.5 weight percent Na₂O+K₂O+Li₂O.

In some embodiments, a fiber glass strand of the present inventioncomprises a plurality of glass fibers comprising a glass compositionthat comprises the following components:

SiO₂ from about 51 to about 70 weight percent; Al₂O₃ from about 12.5 toabout 22 weight percent; CaO from about 0 to about 20 weight percent;MgO from about 0 to about 11 weight percent; Fe₂O₃ from about 0.2 toabout 1 weight percent; RE₂O₃ about 0.05 or greater weight percent; andCu₂O from greater than about 0 to about 2.5 weight percent.

In some embodiments, the composition comprises 0.5 weight percent orgreater Cu₂O. In some embodiments, RE₂O₃ comprises at least one ofLa₂O₃, Y₂O₃, Sc₂O₃, and Nd₂O₃. RE₂O₃ is present in an amount of at leastabout 1 weight percent in some embodiments. In some embodiments, thecomposition further comprises less than about 1.5 weight percentNa₂O+K₂O+Li₂O.

In some embodiments, a fiber glass strand of the present inventioncomprises a plurality of glass fibers comprising a glass compositionthat comprises the following components:

SiO₂ from about 51 to about 70 weight percent; Al₂O₃ from about 12.5 toabout 22 weight percent; CaO from about 0 to about 20 weight percent;MgO from about 0 to about 12.5 weight percent; Fe₂O₃ from about 0.2 toabout 1 weight percent; RE₂O₃ about 0.05 or greater weight percent;and

at least one additional feature selected from the group consisting of:

-   -   La₂O₃ is present in an amount greater than about 2 weight        percent;    -   CaO is present in an amount less than about 2 weight percent;    -   a MgO/CaO ratio less than about 1; and    -   a SiO₂/Al₂O₃ ratio greater than about 4.

In some embodiments, the additional feature comprises La₂O₃ in an amountof about 3 weight percent or greater. In some embodiments, MgO ispresent in an amount greater than about 6 weight percent, and theadditional feature comprises CaO in an amount less than about 1.5 weightpercent. In some embodiments, the additional feature comprises theSiO₂/Al₂O₃ ratio in an amount greater than about 4.2. In someembodiments, RE₂O₃ comprises at least one of La₂O₃, Y₂O₃, Sc₂O₃, andNd₂O₃. RE₂O₃ is present in an amount of at least about 1 weight percentin some embodiments. In some embodiments, the composition furthercomprises less than about 1.5 weight percent Na₂O+K₂O+Li₂O.

A number of other glass compositions are disclosed herein as part of thepresent invention, and other embodiments of the present invention relateto fiber glass strands formed from such compositions.

In some embodiments, glass fibers of the present invention can exhibitdesirable mechanical and other properties. Glass fibers of the presentinvention, in some embodiments, can exhibit one or more improvedmechanical properties relative to glass fibers formed from E-glass. Insome embodiments, glass fibers of the present invention can provide oneor more improved properties relative to glass fibers formed from R-glassand/or S-glass. Examples of desirable properties exhibited by someembodiments of glass fibers of the present invention include, withoutlimitation, tensile strength, Young's modulus, coefficient of thermalexpansion, softening point, elongation, and dielectric constant.

Glass fibers of the present invention can have desirable Young's modulus(E) values in some embodiments. In some embodiments, fibers formed fromglass compositions of the present invention can have a Young's modulusgreater than about 87 GPa. In some embodiments, glass fibers of thepresent invention can have a Young's modulus greater than about 90 GPa.Fibers formed from glass compositions of the present invention can havea Young's modulus greater than about 92 GPa in some embodiments. In someembodiments, glass fibers of the present invention can have a Young'smodulus greater than about 93 GPa. Glass fibers of the present inventioncan have a Young's modulus greater than about 95 GPa in someembodiments. Unless otherwise stated herein, Young's modulus valuesdiscussed herein are determined using the procedure set forth in theExamples section below.

Glass fibers of the present invention, in some embodiments, can havedesirable tensile strengths. In some embodiments, glass fibers of thepresent invention can have a tensile strength greater than 4000 MPa.Glass fibers of the present invention, in some embodiments, can have atensile strength greater than 4,500 MPa. In some embodiments, glassfibers of the present invention can have a tensile strength greater thanabout 5000 MPa. Glass fibers of the present invention, in someembodiments, can have a tensile strength greater than about 5500 MPa.Unless otherwise stated herein, tensile strength values are determinedusing the procedure set forth in the Examples section.

Glass fibers of the present invention, in some embodiments, can havedesirable elongation values. In some embodiments, glass fibers of thepresent invention can have an elongation of at least 5.0%. Glass fibersof the present invention can have an elongation of at least 5.5% in someembodiments. Unless otherwise stated herein, elongation values aredetermined using the procedure set forth in the Examples section.

Glass fibers of the present invention, in some embodiments, can havedesirable coefficients of thermal expansion. In some embodiments, glassfibers of the present invention can have a coefficient of thermalexpansion less than about 4.5 ppm/° C. Glass fibers of the presentinvention, in some embodiments, can have a coefficient of thermalexpansion less than about 3.1 ppm/° C. Unless otherwise stated,coefficients of thermal expansion are determined using the procedure setforth in the Examples section.

Glass fibers of the present invention, in some embodiments, can havedesirable softening points. In some embodiments, glass fibers of thepresent invention can have a softening point of at least about 900° C.Glass fibers of the present invention, in some embodiments, can have asoftening point of at least about 950° C. Unless otherwise stated,softening point values are determined using the procedure set forth inthe Examples section.

Glass fibers of the present invention, in some embodiments, can havedielectric constant values (D_(k)) desirable for use in electronicsapplications. In some embodiments, glass fibers of the present inventioncan have a dielectric constant value (D_(k)) of less than about 6.0 at 1MHz frequency. Unless otherwise stated herein, dielectric constant(D_(k)) is determined from 1 MHz to 1 GHz by ASTM Test MethodD150—“Standard Test Methods for A-C Loss Characteristics andPermittivity (Dielectric Constant) of Solid Electrical InsulatingMaterials.”

Fiber glass strands can comprise glass fibers of various diameters,depending on the desired application. In some embodiments, a fiber glassstrand of the present invention comprises at least one glass fiberhaving a diameter between about 5 and about 18 μm. In other embodiments,the at least one glass fiber has a diameter between about 5 and about 10μm.

In some embodiments, fiber glass strands of the present invention can beformed into rovings. Rovings can comprise assembled, multi-end, orsingle-end direct draw rovings. Rovings comprising fiber glass strandsof the present invention can comprise direct draw single-end rovingshaving various diameters and densities, depending on the desiredapplication. In some embodiments, a roving comprising fiber glassstrands of the present invention exhibits a density up to about 112yards/pound.

Some embodiments of the present invention relate to yarns comprising atleast one fiber glass strand as disclosed herein. In some embodiments, ayarn of the present invention comprises at least one fiber glass strandcomprising a glass composition that comprises from about 51 to about 70weight percent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃,from about 0 to about 20 weight percent CaO, from about 0 to about 11weight percent MgO, from about 0.2 to about 1 weight percent Fe₂O₃,about 0.05 or greater weight percent RE₂O₃, and greater than about 1weight percent MnO_(x). A yarn, in some embodiments, comprises at leastone fiber glass strand comprising a glass composition that comprisesfrom about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, a yarn of the present invention comprises at least onefiber glass strand comprising a glass composition that comprises fromabout 51 to about 70 weight percent SiO₂, from about 12.5 to about 22weight percent Al₂O₃, from about 0 to about 20 weight percent CaO, fromabout 0 to about 11 weight percent MgO, from about 0.2 to about 1 weightpercent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and fromgreater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, a yarn of the present invention comprises at least onefiber glass strand comprising a glass composition that comprises fromabout 51 to about 70 weight percent SiO₂, from about 12.5 to about 22weight percent Al₂O₃, from about 0 to about 20 weight percent CaO, fromabout 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, a yarn of the present invention can comprise at least onefiber glass strand comprising one of the other glass compositionsdisclosed herein as part of the present invention.

In some embodiments, a yarn of the present invention comprises at leastone fiber glass strand as disclosed herein, wherein the at least onefiber glass strand is at least partially coated with a sizingcomposition. In some embodiments, the sizing composition is compatiblewith a thermosetting polymeric resin. In other embodiments, the sizingcomposition can comprise a starch-oil sizing composition.

Yarns can have various linear mass densities, depending on the desiredapplication. In some embodiments, a yarn of the present invention has alinear mass density from about 5,000 yards/pound to about 10,000yards/pound.

Yarns can have various twist levels and directions, depending on thedesired application. In some embodiments, a yarn of the presentinvention has a twist in the z direction of about 0.5 to about 2 turnsper inch. In other embodiments, a yarn of the present invention has atwist in the z direction of about 0.7 turns per inch.

Yarns can be made from one or more strands that are twisted togetherand/or plied, depending on the desired application. Yarns can be madefrom one or more strands that are twisted together but not plied; suchyarns are known as “singles.” Yarns of the present invention can be madefrom one or more strands that are twisted together but not plied. Insome embodiments, yarns of the present invention comprise 1-4 strandstwisted together. In other embodiments, yarns of the present inventioncomprise 1 twisted strand.

Some embodiments of the present invention relate to fabrics comprisingat least one fiber glass strand as disclosed herein. In someembodiments, a fabric of the present invention comprises from about 51to about 70 weight percent SiO₂, from about 12.5 to about 22 weightpercent Al₂O₃, from about 0 to about 20 weight percent CaO, from about 0to about 11 weight percent MgO, from about 0.2 to about 1 weight percentFe₂O₃, about 0.05 or greater weight percent RE₂O₃, and greater thanabout 1 weight percent MnO_(x). A fabric, in some embodiments, comprisesfrom about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, a fabric of the present invention comprises at least onefiber glass strand comprising a glass composition that comprises fromabout 51 to about 70 weight percent SiO₂, from about 12.5 to about 22weight percent Al₂O₃, from about 0 to about 20 weight percent CaO, fromabout 0 to about 11 weight percent MgO, from about 0.2 to about 1 weightpercent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and fromgreater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, a fabric of the present invention comprises at least onefiber glass strand comprising a glass composition that comprises fromabout 51 to about 70 weight percent SiO₂, from about 12.5 to about 22weight percent Al₂O₃, from about 0 to about 20 weight percent CaO, fromabout 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, a fabric of the present invention can comprise at least onefiber glass strand comprising one of the other glass compositionsdisclosed herein as part of the present invention.

In some embodiments of the present invention comprising a fabric, theglass fiber fabric is a fabric woven in accordance with industrialfabric style no. 7781. In other embodiments, the fabric comprises aplain weave fabric, a twill fabric, a crowfoot fabric, a satin weavefabric, a stitch bonded fabric (also known as a non-crimp fabric), or a“three-dimensional” woven fabric. Some embodiments of the presentinvention relate to composites. In some embodiments, a composite of thepresent invention comprises a polymeric resin and a plurality of glassfibers disposed in the polymeric resin, wherein at least one of theplurality of glass fibers comprises a glass composition that comprisesthe following components: from about 51 to about 70 weight percent SiO₂,from about 12.5 to about 22 weight percent Al₂O₃, from about 0 to about20 weight percent CaO, from about 0 to about 11 weight percent MgO, fromabout 0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greater weightpercent RE₂O₃, and greater than about 1 weight percent MnO_(x). Acomposite of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, a composite of the present invention comprises a polymericresin and a plurality of glass fibers disposed in the polymeric resin,wherein at least one of the plurality of glass fibers comprises a glasscomposition that comprises the following components: from about 51 toabout 70 weight percent SiO₂, from about 12.5 to about 22 weight percentAl₂O₃, from about 0 to about 20 weight percent CaO, from about 0 toabout 11 weight percent MgO, from about 0.2 to about 1 weight percentFe₂O₃, about 0.05 or greater weight percent RE₂O₃, and from greater thanabout 0 to about 2.5 weight percent Cu₂O. In some embodiments, acomposite of the present invention comprises a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers comprises a glass compositionthat comprises the following components: from about 51 to about 70weight percent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃,from about 0 to about 20 weight percent CaO, from about 0 to about 12.5weight percent MgO, from about 0.2 to about 1 weight percent Fe₂O₃,about 0.05 or greater weight percent RE₂O₃, and at least one additionalfeature selected from the group consisting of La₂O₃ is present in anamount greater than about 2 weight percent, CaO is present in an amountless than about 2 weight percent, a MgO/CaO ratio less than about 1, anda SiO₂/Al₂O₃ ratio greater than about 4.

In other embodiments, a composite of the present invention can comprisea polymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberswas formed from one of the other glass compositions disclosed herein aspart of the present invention. In some embodiments, a composite of thepresent invention comprises a polymeric resin and at least one fiberglass strand as disclosed herein disposed in the polymeric resin. Insome embodiments, a composite of the present invention comprises apolymeric resin and at least a portion of a roving comprising at leastone fiber glass strand as disclosed herein disposed in the polymericresin. In other embodiments, a composite of the present inventioncomprises a polymeric resin and at least one yarn as disclosed hereindisposed in the polymeric resin. In still other embodiments, a compositeof the present invention comprises a polymeric resin and at least onefabric as disclosed herein disposed in the polymeric resin. In someembodiments, a composite of the present invention comprises at least onefill yarn comprising at least one fiber glass strand as disclosed hereinand at least one warp yarn comprising at least one fiber glass strand asdisclosed herein.

Composites of the present invention can comprise various polymericresins, depending on the desired properties and applications. In someembodiments of the present invention comprising a composite, thepolymeric resin comprises an epoxy resin. In other embodiments of thepresent invention comprising a composite, the polymeric resin cancomprise polyethylene, polypropylene, polyamide, polyimide, polybutyleneterephthalate, polycarbonate, thermoplastic polyurethane, phenolic,polyester, vinyl ester, polydicyclopentadiene, polyphenylene sulfide,polyether ether ketone, cyanate esters, bis-maleimides, and thermosetpolyurethane resins.

Some embodiments of the present invention relate to aerospacecomposites. In some embodiments, an aerospace composite of the presentinvention exhibits properties desirable for use in aerospaceapplications, such as high strength, high elongation, high modulus,and/or low density.

In some embodiments, an aerospace composite of the present inventioncomprises a polymeric resin and a plurality of glass fibers disposed inthe polymeric resin, wherein at least one of the plurality of glassfibers comprises a glass composition that comprises the followingcomponents: from about 51 to about 70 weight percent SiO₂, from about12.5 to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and greater than about 1 weight percent MnO_(x). An aerospacecomposite of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, an aerospace composite of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andfrom greater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, an aerospace composite of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, an aerospace composite of the present invention cancomprise a polymeric resin and a plurality of glass fibers disposed inthe polymeric resin, wherein at least one of the plurality of glassfibers was formed from one of the other glass compositions disclosedherein as part of the present invention.

In some embodiments, an aerospace composite of the present inventioncomprises a polymeric resin and at least one fiber glass strand asdisclosed herein disposed in the polymeric resin. In some embodiments,an aerospace composite of the present invention comprises a polymericresin and at least a portion of a roving comprising at least one fiberglass strand as disclosed herein disposed in the polymeric resin. Inother embodiments, an aerospace composite of the present inventioncomprises a polymeric resin and at least one yarn as disclosed hereindisposed in the polymeric resin. In still other embodiments, anaerospace composite of the present invention comprises a polymeric resinand at least one fabric as disclosed herein disposed in the polymericresin. In some embodiments, an aerospace composite of the presentinvention comprises at least one fill yarn comprising at least one fiberglass strand as disclosed herein and at least one warp yarn comprisingat least one fiber glass strand as disclosed herein.

Aerospace composites of the present invention can comprise variouspolymeric resins, depending on the desired properties and applications.In some embodiments of the present invention comprising an aerospacecomposite, the polymeric resin comprises an epoxy resin. In otherembodiments of the present invention comprising an aerospace composite,the polymeric resin can comprise polyethylene, polypropylene, polyamide,polyimide, polybutylene terephthalate, polycarbonate, thermoplasticpolyurethane, phenolic, polyester, vinyl ester, polydicyclopentadiene,polyphenylene sulfide, polyether ether ketone, cyanate esters,bis-maleimides, and thermoset polyurethane resins. Examples of parts inwhich aerospace composites of the present invention might be used caninclude, but are not limited to floor panels, overhead bins, galleys,seat back, and other internal compartments that are potentially prone toimpact, as well as external components such as helicopter rotor blades.

Some embodiments of the present invention relate to aviation composites.In some embodiments, an aviation composite of the present inventionexhibits properties desirable for use in aviation applications, such ashigh strength, high elongation, high modulus, lower density, highspecific strength, and/or high specific modulus. The high elongation ofsome aviation composites of the present invention can make suchcomposites especially desirable for use in aviation applications inwhich high impact resistance is important, such as aircraft interiorapplications. In some embodiments, aviation composites of the presentinvention can demonstrate increased impact performance as compared tocomposites formed from E-glass fabrics. Aviation composites of thepresent invention can be suitable for use in aircraft interiors(including, among other things, luggage storage bins, seats, andfloors).

In some embodiments, an aviation composite of the present inventioncomprises a polymeric resin and a plurality of glass fibers disposed inthe polymeric resin, wherein at least one of the plurality of glassfibers comprises a glass composition that comprises the followingcomponents: from about 51 to about 70 weight percent SiO₂, from about12.5 to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and greater than about 1 weight percent MnO_(x). An aviationcomposite of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, an aviation composite of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andfrom greater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, an aviation composite of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, an aviation composite of the present invention can comprisea polymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberswas formed from one of the other glass compositions disclosed herein aspart of the present invention.

In some embodiments, an aviation composite of the present inventioncomprises a polymeric resin and at least one fiber glass strand asdisclosed herein disposed in the polymeric resin. In some embodiments,an aviation composite of the present invention comprises a polymericresin and at least a portion of a roving comprising at least one fiberglass strand as disclosed herein disposed in the polymeric resin. Inother embodiments, an aviation composite of the present inventioncomprises a polymeric resin and at least one yarn as disclosed hereindisposed in the polymeric resin. In still other embodiments, an aviationcomposite of the present invention comprises a polymeric resin and atleast one fabric as disclosed herein disposed in the polymeric resin. Insome embodiments, an aviation composite of the present inventioncomprises at least one fill yarn comprising at least one fiber glassstrand as disclosed herein and at least one warp yarn comprising atleast one fiber glass strand as disclosed herein.

Aviation composites of the present invention can comprise variouspolymeric resins, depending on the desired properties and applications.In some embodiments of the present invention comprising an aviationcomposite, the polymeric resin comprises a phenolic resin. In otherembodiments of the present invention comprising an aviation composite,the polymeric resin can comprise epoxy, polyethylene, polypropylene,polyamide, polyimide, polybutylene terephthalate, polycarbonate,thermoplastic polyurethane, phenolic, polyester, vinyl ester,polydicyclopentadiene, polyphenylene sulfide, polyether ether ketone,cyanate esters, bis-maleimides, and thermoset polyurethane resins.Examples of parts in which aviation composites of the present inventionmight be used can include, but are not limited to, floor panels,overhead bins, galleys, seat back, and other internal compartments thatare potentially prone to impact, as well as external components such ashelicopter rotor blades.

Some embodiments of the present invention relate to automotivecomposites. In some embodiments, an automotive composite of the presentinvention exhibits properties desirable for use in automotiveapplications, such as high strength, high elongation and low fiberdensity. The combination of high strength and high elongation (orfailure-to-strain) of some composites of the present invention can makesuch composites especially desirable for use in automotive applicationsin which high impact resistance is important, such as automobilestructural components, bodies, and bumpers. In some embodiments,automotive composites of the present invention can demonstrate increasedimpact performance as compared to composites formed from E-glassfabrics, R-glass fabrics, and/or S-glass fabrics.

In some embodiments, an automotive composite of the present inventioncomprises a polymeric resin and a plurality of glass fibers disposed inthe polymeric resin, wherein at least one of the plurality of glassfibers comprises a glass composition that comprises the followingcomponents: from about 51 to about 70 weight percent SiO₂, from about12.5 to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, and greater than about 1 weight percent MnO_(x). An automotivecomposite of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, an automotive composite of the present invention comprisesa polymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andfrom greater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, an automotive composite of the present invention comprisesa polymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, an automotive composite of the present invention cancomprise a polymeric resin and a plurality of glass fibers disposed inthe polymeric resin, wherein at least one of the plurality of glassfibers was formed from one of the other glass compositions disclosedherein as part of the present invention.

In some embodiments, an automotive composite of the present inventioncomprises a polymeric resin and at least one fiber glass strand asdisclosed herein disposed in the polymeric resin. In some embodiments,an automotive composite of the present invention comprises a polymericresin and at least a portion of a roving comprising at least one fiberglass strand as disclosed herein disposed in the polymeric resin. Inother embodiments, an automotive composite of the present inventioncomprises a polymeric resin and at least one yarn as disclosed hereindisposed in the polymeric resin. In still other embodiments, anautomotive composite of the present invention comprises a polymericresin and at least one fabric as disclosed herein disposed in thepolymeric resin. In some embodiments, an automotive composite of thepresent invention comprises at least one fill yarn comprising at leastone fiber glass strand as disclosed herein and at least one warp yarncomprising at least one fiber glass strand as disclosed herein.

Automotive composites of the present invention can comprise variouspolymeric resins, depending on the desired properties and applications.In some embodiments of the present invention comprising an automotivecomposite, the polymeric resin can comprise a thermoplastic resin or athermosetting resin. Examples of common thermoplastic resins used inautomotive composites include, without limitation, polypropylene,polyamide, high temperature polyamide, polyester, and otherthermoplastic resins known to those of skill in the art. Examples ofcommon thermosetting resins used in automotive composites include,without limitation, epoxy, phenolic, polyester, and other thermosettingresins known to those of skill in the art. Examples of parts in whichautomotive composites of the present invention might be used caninclude, but are not limited to, automobile structural components,bodies, and bumpers.

Some embodiments of the present invention relate to composites that canbe used in wind energy applications. In some embodiments, a composite ofthe present invention suitable for use in wind energy applicationsexhibits properties desirable for use in wind energy applications, suchas high modulus, high elongation, low fiber density, and/or highspecific modulus. Composites of the present invention can be suitablefor use in wind turbine blades, particularly long wind turbine bladesthat are lighter weight but still strong compared to other long windturbine blades.

In some embodiments, a composite of the present invention suitable foruse in wind energy applications comprises a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers comprises a glass compositionthat comprises the following components: from about 51 to about 70weight percent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃,from about 0 to about 20 weight percent CaO, from about 0 to about 11weight percent MgO, from about 0.2 to about 1 weight percent Fe₂O₃,about 0.05 or greater weight percent RE₂O₃, and greater than about 1weight percent MnO_(x). A composite of the present invention suitablefor use in wind energy applications, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, a composite of the present invention suitable for use inwind energy applications comprises a polymeric resin and a plurality ofglass fibers disposed in the polymeric resin, wherein at least one ofthe plurality of glass fibers comprises a glass composition thatcomprises the following components: from about 51 to about 70 weightpercent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃, fromabout 0 to about 20 weight percent CaO, from about 0 to about 11 weightpercent MgO, from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05or greater weight percent RE₂O₃, and from greater than about 0 to about2.5 weight percent Cu₂O. In some embodiments, a composite of the presentinvention suitable for use in wind energy applications comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, a composite suitable for use in wind energy applications ofthe present invention can comprise a polymeric resin and a plurality ofglass fibers disposed in the polymeric resin, wherein at least one ofthe plurality of glass fibers was formed from one of the other glasscompositions disclosed herein as part of the present invention.

In some embodiments, a composite of the present invention suitable foruse in wind energy applications comprises a polymeric resin and at leastone fiber glass strand as disclosed herein disposed in the polymericresin. In some embodiments, a composite of the present inventionsuitable for use in wind energy applications comprises a polymeric resinand at least a portion of a roving comprising at least one fiber glassstrand as disclosed herein disposed in the polymeric resin. In otherembodiments, a composite of the present invention suitable for use inwind energy applications comprises a polymeric resin and at least oneyarn as disclosed herein disposed in the polymeric resin. In still otherembodiments, a composite of the present invention suitable for use inwind energy applications comprises a polymeric resin and at least onefabric as disclosed herein disposed in the polymeric resin. In someembodiments, a composite of the present invention suitable for use inwind energy applications comprises at least one fill yarn comprising atleast one fiber glass strand as disclosed herein and at least one warpyarn comprising at least one fiber glass strand as disclosed herein.

Composites of the present invention suitable for use in wind energyapplications can comprise various polymeric resins, depending on thedesired properties and applications. In some embodiments of the presentinvention comprising a composite suitable for use in wind energyapplications, the polymeric resin comprises an epoxy resin. In otherembodiments of the present invention comprising a composite suitable foruse in wind energy applications, the polymeric resin can comprisepolyester resins, vinyl esters, thermoset polyurethanes, orpolydicyclopentadiene resins.

Some embodiments of the present invention relate to composites for usein high pressure vessels and/or tanks. In some embodiments, a compositefor use in high pressure vessels and/or tanks of the present inventionexhibits properties desirable for use in such applications, such as highstrength, high elongation, low density, and/or high specific strength.

In some embodiments, a composite for use in high pressure vessels and/ortanks of the present invention comprises a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers comprises a glass compositionthat comprises the following components: from about 51 to about 70weight percent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃,from about 0 to about 20 weight percent CaO, from about 0 to about 11weight percent MgO, from about 0.2 to about 1 weight percent Fe₂O₃,about 0.05 or greater weight percent RE₂O₃, and greater than about 1weight percent MnO_(x). A composite for use in high pressure vesselsand/or tanks of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent. In someembodiments, a composite for use in high pressure vessels and/or tanksof the present invention comprises a polymeric resin and a plurality ofglass fibers disposed in the polymeric resin, wherein at least one ofthe plurality of glass fibers comprises a glass composition thatcomprises the following components: from about 51 to about 70 weightpercent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃, fromabout 0 to about 20 weight percent CaO, from about 0 to about 11 weightpercent MgO, from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05or greater weight percent RE₂O₃, and from greater than about 0 to about2.5 weight percent Cu₂O. In some embodiments, a composite for use inhigh pressure vessels and/or tanks of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 12.5 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and atleast one additional feature selected from the group consisting of La₂O₃is present in an amount greater than about 2 weight percent, CaO ispresent in an amount less than about 2 weight percent, a MgO/CaO ratioless than about 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, a composite for use in high pressure vessels and/or tanksof the present invention can comprise a polymeric resin and a pluralityof glass fibers disposed in the polymeric resin, wherein at least one ofthe plurality of glass fibers was formed from one of the other glasscompositions disclosed herein as part of the present invention.

In some embodiments, a composite for use in high pressure vessels and/ortanks of the present invention comprises a polymeric resin and at leastone fiber glass strand as disclosed herein disposed in the polymericresin. In some embodiments, a composite for use in high pressure vesselsand/or tanks of the present invention comprises a polymeric resin and atleast a portion of a roving comprising at least one fiber glass strandas disclosed herein disposed in the polymeric resin. In otherembodiments, a composite for use in high pressure vessels and/or tanksof the present invention comprises a polymeric resin and at least oneyarn as disclosed herein disposed in the polymeric resin. In still otherembodiments, a composite for use in high pressure vessels and/or tanksof the present invention comprises a polymeric resin and at least onefabric as disclosed herein disposed in the polymeric resin. In someembodiments, a composite for use in high pressure vessels and/or tanksof the present invention comprises at least one fill yarn comprising atleast one fiber glass strand as disclosed herein and at least one warpyarn comprising at least one fiber glass strand as disclosed herein.

Composites for use in high pressure vessels and/or tanks of the presentinvention can comprise various polymeric resins, depending on thedesired properties and applications. In some embodiments of the presentinvention comprising a composite for use in high pressure vessels and/ortanks, the polymeric resin can comprise a thermosetting resin. Examplesof common thermosetting resins used in high pressure vessels and/ortanks include, without limitation, epoxy, phenolic, polyester, vinylester and other thermosetting resins known to those of skill in the art.

In some embodiments, composites of the present invention can be usefulin safety and/or security applications. For example, composites of thepresent invention, in some embodiments, are suitable for use in highmechanical stress applications, including, but not limited to, highenergy impact applications. Glass fibers useful in some embodiments ofthe present invention can exhibit properties especially desirable forhigh energy impact applications such as ballistic or blast resistanceapplications. Compared to glass fibers comprising E-glass, glass fibersuseful in some embodiments of the present invention can exhibit lowdielectric constant, low dielectric loss, high glass transitiontemperature and/or low thermal expansion.

In some embodiments, composites of the present invention can be suitablefor use in armor applications. For example, some embodiments ofcomposites can be used in the production of armor panels. In someembodiments, a composite of the present invention can be formed into apanel, wherein the panel are expected to exhibit desirable 0.30 cal FSP(“fragment simulating projectile”) V50 values (e.g., at least about 900feet per second (fps) at a panel areal density of about 2 lb/ft² and apanel thickness of about 5-6 mm) when measured by the U.S. Department ofDefense Test Method Standard for V50 Ballistic Test for Armor,MIL-STD-662F, December 1997 (hereinafter “MIL-STD-662F”), the entiretyof which is incorporated herein by reference. In this context, the term“composite” refers generically to a material comprising a polymericresin and a plurality of glass fibers disposed in the polymeric resin,whereas the term “panel” refers to a composite having sheet-likephysical dimensions or shape. In other embodiments, a composite of thepresent invention can be formed into a panel, wherein the panel isexpected to exhibit desirable 0.50 cal FSP V50 values (e.g., at leastabout 1200 fps at a panel areal density of about 4.8-4.9 lb/ft² and apanel thickness of about 13-13.5 mm) when measured by MIL-STD-662F. AsV50 values can depend on the panel areal density and the panelthickness, composites of the present invention can have different V50values depending on how the panel is constructed. One advantage of someembodiments of the present invention is the provision of compositeshaving higher V50 values than similarly constructed composites assembledusing E-glass fibers.

In some embodiments, a composite of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andgreater than about 1 weight percent MnO_(x), wherein the composite isadapted for use in ballistics or blast resistance applications. Acomposite of the present invention, in some embodiments, comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, fromabout 0 to about 4 weight percent BaO, from about 0 to about 4 weightpercent SrO, and from about 0 to about 5.5 weight percent ZrO, whereinthe sum of BaO+SrO+ZnO is greater than about 2 weight percent, andwherein the composite is adapted for use in ballistics or blastresistance applications. In some embodiments, a composite of the presentinvention comprises a polymeric resin and a plurality of glass fibersdisposed in the polymeric resin, wherein at least one of the pluralityof glass fibers comprises a glass composition that comprises thefollowing components: from about 51 to about 70 weight percent SiO₂,from about 12.5 to about 22 weight percent Al₂O₃, from about 0 to about20 weight percent CaO, from about 0 to about 11 weight percent MgO, fromabout 0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greater weightpercent RE₂O₃, and from greater than about 0 to about 2.5 weight percentCu₂O, wherein the composite is adapted for use in ballistics or blastresistance applications. In some embodiments, a composite of the presentinvention comprises a polymeric resin and a plurality of glass fibersdisposed in the polymeric resin, wherein at least one of the pluralityof glass fibers comprises a glass composition that comprises thefollowing components: from about 51 to about 70 weight percent SiO₂,from about 12.5 to about 22 weight percent Al₂O₃, from about 0 to about20 weight percent CaO, from about 0 to about 12.5 weight percent MgO,from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greaterweight percent RE₂O₃, and at least one additional feature selected fromthe group consisting of La₂O₃ is present in an amount greater than about2 weight percent, CaO is present in an amount less than about 2 weightpercent, a MgO/CaO ratio less than about 1, and a SiO₂/Al₂O₃ ratiogreater than about 4, wherein the composite is adapted for use inballistics or blast resistance applications. In other embodiments, acomposite of the present invention adapted for use in ballistics orblast resistance applications can comprise a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers was formed from one of theother glass compositions disclosed herein as part of the presentinvention.

Some embodiments of the present invention relate to panels, such asarmor panels, comprising composites of the present invention. In someembodiments, a composite of the present invention can be formed into apanel, wherein the panel is expected to exhibit desirable 0.30 cal FSPV50 values (e.g., at least about 900 fps at a panel areal density ofabout 2 lb/ft² and a panel thickness of about 5-6 mm) when measured byMIL-STD-662F. In other embodiments, a composite of the present inventioncan be formed into a panel, wherein the panel is expected to exhibitdesirable 0.30 cal FSP V50 values (e.g., at least about 1000 fps at apanel areal density of about 2 lb/ft² and a panel thickness of about 5-6mm) when measured by MIL-STD-662F. In still other embodiments of thepresent invention, a composite can be formed into a panel, wherein thepanel is expected to exhibit desirable 0.30 cal FSP V50 values (e.g., atleast about 1100 fps at a panel areal density of about 2 lb/ft² and apanel thickness of about 5-6 mm) when measured MIL-STD-662F. In someembodiments of the present invention, a composite can be formed into apanel, wherein the panel is expected to exhibit desirable 0.30 cal FSPV50 values (e.g., about 900 fps to about 1140 fps at a panel arealdensity of about 2 lb/ft² and a panel thickness of about 5-6 mm) whenmeasured by MIL-STD-662F.

In some embodiments, a composite of the present invention can be formedinto a panel, wherein the panel is expected to exhibit desirable 0.50cal FSP V50 values (e.g., at least about 1200 fps at a panel arealdensity of about 4.8-4.9 lb/ft² and a panel thickness of about 13-13.5mm) when measured by MIL-STD-662F. In other embodiments of the presentinvention, a composite can be formed into a panel, wherein the panel isexpected to exhibit desirable 0.50 cal FSP V50 values (at least about1300 fps at a panel areal density of about 4.8-4.9 lb/ft² and a panelthickness of about 13-13.5 mm) when measured by MIL-STD-662F. In stillother embodiments of the present invention, a composite can be formedinto a panel, wherein the panel is expected to exhibit desirable 0.50cal FSP V50 values (at least about 1400 fps at a panel areal density ofabout 4.8-4.9 lb/ft² and a panel thickness of about 13-13.5 mm) whenmeasured by MIL-STD-662F. In some embodiments of the present invention,a composite can be formed into a panel, wherein the panel is expected toexhibit desirable 0.50 cal FSP V50 values (e.g., about 1200 fps to about1440 fps at a panel areal density of about 4.8-4.9 lb/ft² and a panelthickness of about 13-13.5 mm) when measured by MIL-STD-662F.

Composites of the present invention adapted for use in ballistics orblast resistance can comprise various polymeric resins. In someembodiments of the present invention, a composite comprises a polymericresin and a plurality of glass fibers disposed in the polymeric resin,wherein at least one of the plurality of glass fibers comprises a glasscomposition as disclosed herein, the composite can be formed into apanel, such as an armor panel for ballistic or blast resistance, and thepolymeric resin comprises an epoxy resin. A composite of the presentinvention, in some embodiments, comprises a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers comprises a glass compositionas disclosed herein, the composite can be formed into a panel, such asan armor panel for ballistic or blast resistance, and the polymericresin comprises a polydicyclopentadiene resin. In some embodiments ofthe present invention, the polymeric resin can comprise polyethylene,polypropylene, polyamides (including Nylon), polybutylene terephthalate,polycarbonate, thermoplastic polyurethane, phenolic, polyester, vinylester, thermoset polyurethane, cyanate esters, or bis-maleimide resins.

Some embodiments of the present invention relate to composites for usein casings for missiles and other explosive delivery devices. In someembodiments, a composite for use in casings for missiles and otherexplosive delivery devices of the present invention exhibits propertiesdesirable for use in such applications, such as high modulus, highstrength, high elongation, low coefficient of thermal expansion, highglass softening temperature, and/or high glass transition temperature.

In some embodiments, a composite for use in casings for missiles andother explosive delivery devices of the present invention comprises apolymeric resin and a plurality of glass fibers disposed in thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andgreater than about 1 weight percent MnO_(x). A composite for use incasings for missiles and other explosive delivery devices of the presentinvention, in some embodiments, comprises a polymeric resin and aplurality of glass fibers disposed in the polymeric resin, wherein atleast one of the plurality of glass fibers comprises a glass compositionthat comprises the following components: from about 51 to about 70weight percent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃,from about 0 to about 20 weight percent CaO, from about 0 to about 11weight percent MgO, from about 0.2 to about 1 weight percent Fe₂O₃,about 0.05 or greater weight percent RE₂O₃, from about 0 to about 4weight percent BaO, from about 0 to about 4 weight percent SrO, and fromabout 0 to about 5.5 weight percent ZrO, wherein the sum of BaO+SrO+ZnOis greater than about 2 weight percent. In some embodiments a compositefor use in casings for missiles and other explosive delivery devices ofthe present invention comprises a polymeric resin and a plurality ofglass fibers disposed in the polymeric resin, wherein at least one ofthe plurality of glass fibers comprises a glass composition thatcomprises the following components: from about 51 to about 70 weightpercent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃, fromabout 0 to about 20 weight percent CaO, from about 0 to about 11 weightpercent MgO, from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05or greater weight percent RE₂O₃, and from greater than about 0 to about2.5 weight percent Cu₂O. In some embodiments a composite for use incasings for missiles and other explosive delivery devices of the presentinvention comprises a polymeric resin and a plurality of glass fibersdisposed in the polymeric resin, wherein at least one of the pluralityof glass fibers comprises a glass composition that comprises thefollowing components: from about 51 to about 70 weight percent SiO₂,from about 12.5 to about 22 weight percent Al₂O₃, from about 0 to about20 weight percent CaO, from about 0 to about 12.5 weight percent MgO,from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05 or greaterweight percent RE₂O₃, and at least one additional feature selected fromthe group consisting of La₂O₃ is present in an amount greater than about2 weight percent, CaO is present in an amount less than about 2 weightpercent, a MgO/CaO ratio less than about 1, and a SiO₂/Al₂O₃ ratiogreater than about 4. In other embodiments, a composite for use incasings for missiles and other explosive delivery devices of the presentinvention can comprise a polymeric resin and a plurality of glass fibersdisposed in the polymeric resin, wherein at least one of the pluralityof glass fibers was formed from one of the other glass compositionsdisclosed herein as part of the present invention.

In some embodiments, a composite for use in casings for missiles andother explosive delivery devices of the present invention comprises apolymeric resin and at least one fiber glass strand as disclosed hereindisposed in the polymeric resin. In some embodiments, a composite foruse in casings for missiles and other explosive delivery devices of thepresent invention comprises a polymeric resin and at least a portion ofa roving comprising at least one fiber glass strand as disclosed hereindisposed in the polymeric resin. In other embodiments, a composite foruse in casings for missiles and other explosive delivery devices of thepresent invention comprises a polymeric resin and at least one yarn asdisclosed herein disposed in the polymeric resin. In still otherembodiments, a composite for use in casings for missiles and otherexplosive delivery devices of the present invention comprises apolymeric resin and at least one fabric as disclosed herein disposed inthe polymeric resin. In some embodiments, a composite for use in casingsfor missiles and other explosive delivery devices of the presentinvention comprises at least one fill yarn comprising at least one fiberglass strand as disclosed herein and at least one warp yarn comprisingat least one fiber glass strand as disclosed herein.

Composites for use in casings for missiles and other explosive deliverydevices of the present invention can comprise various polymeric resins,depending on the desired properties and applications. In someembodiments of the present invention comprising a composite for use incasings for missiles and other explosive delivery devices, the polymericresin can comprise a thermosetting resin. Examples of commonthermosetting resins that can be used in such applications include,without limitation, epoxy, phenolic, polyester, and other thermosettingresins known to those of skill in the art.

While a number of exemplary uses and applications for composites of thepresent invention are described herein, persons of skill in the art canidentify other potential uses for such composites including, forexample, other applications in the oil and gas industry, otherapplications related to transportation and infrastructure, otherapplications in alternative energy, other high temperature thermalinsulation (i.e., thermal shielding) applications (due to higherstrength, higher modulus, higher softening temperature and higher glasstransition temperature), etc.

Some embodiments of the present invention relate to prepregs. Prepregsof the present invention can comprise a polymeric resin and at least onefiber glass strand as disclosed herein. In some embodiments, a prepregof the present invention comprises a polymeric resin and a plurality ofglass fibers in contact with the polymeric resin, wherein at least oneof the plurality of glass fibers comprises a glass composition thatcomprises the following components: from about 51 to about 70 weightpercent SiO₂, from about 12.5 to about 22 weight percent Al₂O₃, fromabout 0 to about 20 weight percent CaO, from about 0 to about 11 weightpercent MgO, from about 0.2 to about 1 weight percent Fe₂O₃, about 0.05or greater weight percent RE₂O₃, and greater than about 1 weight percentMnO_(x). A prepreg of the present invention, in some embodiments,comprises a polymeric resin and a plurality of glass fibers in contactwith the polymeric resin, wherein at least one of the plurality of glassfibers comprises a glass composition that comprises the followingcomponents: from about 51 to about 70 weight percent SiO₂, from about12.5 to about 22 weight percent Al₂O₃, from about 0 to about 20 weightpercent CaO, from about 0 to about 11 weight percent MgO, from about 0.2to about 1 weight percent Fe₂O₃, about 0.05 or greater weight percentRE₂O₃, from about 0 to about 4 weight percent BaO, from about 0 to about4 weight percent SrO, and from about 0 to about 5.5 weight percent ZrO,wherein the sum of BaO+SrO+ZnO is greater than about 2 weight percent.In some embodiments, a prepreg of the present invention comprises apolymeric resin and a plurality of glass fibers in contact with thepolymeric resin, wherein at least one of the plurality of glass fiberscomprises a glass composition that comprises the following components:from about 51 to about 70 weight percent SiO₂, from about 12.5 to about22 weight percent Al₂O₃, from about 0 to about 20 weight percent CaO,from about 0 to about 11 weight percent MgO, from about 0.2 to about 1weight percent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, andfrom greater than about 0 to about 2.5 weight percent Cu₂O. In someembodiments, a prepreg of the present invention comprises a polymericresin and a plurality of glass fibers in contact with the polymericresin, wherein at least one of the plurality of glass fibers comprises aglass composition that comprises the following components: from about 51to about 70 weight percent SiO₂, from about 12.5 to about 22 weightpercent Al₂O₃, from about 0 to about 20 weight percent CaO, from about 0to about 12.5 weight percent MgO, from about 0.2 to about 1 weightpercent Fe₂O₃, about 0.05 or greater weight percent RE₂O₃, and at leastone additional feature selected from the group consisting of La₂O₃ ispresent in an amount greater than about 2 weight percent, CaO is presentin an amount less than about 2 weight percent, a MgO/CaO ratio less thanabout 1, and a SiO₂/Al₂O₃ ratio greater than about 4. In otherembodiments, a prepreg of the present invention can comprise a polymericresin and a plurality of glass fibers in contact with the polymericresin, wherein at least one of the plurality of glass fibers was formedfrom one of the other glass compositions disclosed herein as part of thepresent invention.

In some embodiments, a prepreg of the present invention comprises apolymeric resin and at least one fiber glass strand as disclosed hereinin contact with the polymeric resin. In some embodiments, a prepreg ofthe present invention comprises a polymeric resin and at least a portionof a roving comprising at least one fiber glass strand as disclosedherein disposed in the polymeric resin. In other embodiments, a prepregof the present invention comprises a polymeric resin and at least oneyarn as disclosed herein in contact with the polymeric resin. In stillother embodiments, a prepreg of the present invention comprises apolymeric resin and at least one fabric as disclosed herein in contactwith the polymeric resin. In some embodiments, a prepreg of the presentinvention comprises at least one fill yarn comprising at least one fiberglass strand as disclosed herein and at least one warp yarn comprisingat least one fiber glass strand as disclosed herein.

Prepregs of the present invention can comprise various polymeric resins,depending on the desired properties and applications. In someembodiments of the present invention comprising a prepreg, the polymericresin comprises an epoxy resin. In other embodiments of the presentinvention comprising a prepreg, the polymeric resin can comprisepolyethylene, polypropylene, polyamide, polyimide, polybutyleneterephthalate, polycarbonate, thermoplastic polyurethane, phenolic,polyester, vinyl ester, polydicyclopentadiene, polyphenylene sulfide,polyether ether ketone, cyanate esters, bis-maleimides, and thermosetpolyurethane resins.

While many of the applications for the glass fibers described herein arereinforcement applications, some embodiments of glass fibers of thepresent invention can be utilized in electronics applications such asprinted circuit boards (“PCB”). More particularly, some embodiments ofthe present invention relate to glass fiber reinforcements that haveelectrical properties that permit enhancing performance of a PCB. Forexample, some embodiments of glass fibers of the present invention canhave a dielectric constant (D_(k)) desirable for electronicsapplications. The dielectric constant of a material (D_(k)), also knownas “permittivity,” is a measure of the ability of a material to storeelectric energy. A material to be used as a capacitor desirably has arelatively high D_(k), whereas a material to be used as part of a PCBsubstrate desirably has a low D_(k), particularly for high speedcircuits. D_(k) is the ratio of the charge that would be stored (i.e.,the capacitance) of a given material between two metal plates to theamount of charge that would be stored by a void (air or vacuum) betweenthe same two metal plates. As another example, some embodiments of glassfibers of the present invention can have a coefficient for thermalexpansion desirable for electronics applications. Accordingly, someembodiments of the present invention can be used in a variety ofelectrical applications including, without limitation, printed circuitboards, precursors to printed circuit boards (e.g., fabrics, laminates,prepregs, etc.). In such embodiments, the printed circuit board or othercomposite to be used in electrical applications can comprise a polymericresin and a plurality of glass fibers in contact with the polymericresin, wherein at least one of the plurality of glass fibers was formedfrom any of the glass compositions disclosed herein as part of thepresent invention. The polymeric resin can include any of those known tothose of skill in the art for use in printed circuit boards or otherelectrical applications.

Turning now to methods of manufacturing glass fibers of the presentinvention and related products, glass fibers of the present inventioncan be prepared in the conventional manner well known in the art, byblending the raw materials used to supply the specific oxides that formthe composition of the fibers. Glass fibers according to the variousembodiments of the present invention can be formed using any processknown in the art for forming glass fibers, and more desirably, anyprocess known in the art for forming essentially continuous glassfibers. For example, although not limiting herein, the glass fibersaccording to non-limiting embodiments of the present invention can beformed using direct-melt or indirect-melt fiber forming methods. Thesemethods are well known in the art and further discussion thereof is notbelieved to be necessary in view of the present disclosure. See, e.g.,K. L. Loewenstein, The Manufacturing Technology of Continuous GlassFibers, 3rd Ed., Elsevier, N.Y., 1993 at pages 47-48 and 117-234.

Following formation of the glass fibers, a primary sizing compositioncan be applied to the glass fibers using any suitable method known toone of ordinary skill in the art. In some embodiments, the sizingcomposition can be applied immediately after forming the glass fibers.In general, glass fibers used to form fiber glass strands, fabrics,composites, laminates, and prepregs of the present invention will be atleast partially coated with a sizing composition. One skilled in the artmay choose one of many commercially available sizing compositions forthe glass fibers based upon a number of factors including, for example,performance properties of the sizing compositions, desired flexibilityof the resulting fabric, cost, and other factors. In some embodiments,the sizing composition does not comprise a starch-oil sizingcomposition. In some embodiments of the present invention comprising asizing composition that does not comprise a starch-oil sizingcomposition, a sized glass fiber or glass fiber strand need not befurther treated with a slashing composition prior to using the fiber orstrand in weaving applications. In other embodiments comprising a sizingcomposition that does not comprise a starch-oil sizing composition, asized glass fiber or glass fiber strand may optionally be furthertreated with a slashing composition prior to using the fiber or strandin weaving applications. In some embodiments of the present inventioncomprising a primary sizing composition, the sizing composition cancomprise a starch-oil sizing composition. In some embodiments of thepresent invention comprising a starch-oil sizing composition, thestarch-oil sizing composition may later be removed from a fabric formedfrom at least one sized glass fiber or fiber glass strand. In someembodiments, the starch-oil sizing may be removed from a fabric usingany suitable method known to one of ordinary skill in the art, such asbut not limited to heat cleaning. In embodiments of the presentinvention comprising fabrics from which a starch-oil sizing compositionhas been removed, a fabric of the present invention may further betreated with a finish coating.

Non-limiting examples of commercially available sizing compositions thatcan be used in some embodiments of the present invention include sizingcompositions often used on single-end rovings, such as Hybon 2026, Hybon2002, Hybon 1383, Hybon 2006, Hybon 2022, Hybon 2032, Hybon 2016, andHybon 1062, as well as sizing compositions often used on yarns, such as1383, 611, 900, 610, 695, and 690, each of which refer to sizingcompositions for products commercially available from PPG Industries,Inc.

Fiber glass strands of the present invention can be prepared by anysuitable method known to one of ordinary skill in the art. Glass fiberfabrics of the present invention can generally be made by any suitablemethod known to one of ordinary skill in the art, such as but notlimited to interweaving weft yarns (also referred to as “fill yarns”)into a plurality of warp yarns. Such interweaving can be accomplished bypositioning the warp yarns in a generally parallel, planar array on aloom, and thereafter weaving the weft yarns into the warp yarns bypassing the weft yarns over and under the warp yarns in a predeterminedrepetitive pattern. The pattern used depends upon the desired fabricstyle.

Warp yarns can generally be prepared using techniques known to those ofskill in the art. Warp yarns can be formed by attenuating a plurality ofmolten glass streams from a bushing or spinner. Thereafter, a sizingcomposition can be applied to the individual glass fibers and the fiberscan be gathered together to form a strand. The strands can besubsequently processed into yarns by transferring the strands to abobbin via a twist frame. During this transfer, the strands can be givena twist to aid in holding the bundle of fibers together. These twistedstrands can then be wound about the bobbin, and the bobbins can be usedin the weaving processes.

Positioning of the warp yarns on the loom can generally be done usingtechniques known to those of ordinary skill in the art. Positioning ofthe warp yarns on the loom can be done by way of a loom beam. A loombeam comprises a specified number of warp yarns (also referred to as“ends”) wound in an essentially parallel arrangement (also referred toas “warp sheet”) about a cylindrical core. Loom beam preparation cancomprise combining multiple yarn packages, each package comprising afraction of the number of ends required for the loom beam, into a singlepackage or loom beam. For example and although not limiting herein, a 50inch (127 cm) wide, 7781 style fabric which utilizes a DE75 yarn inputtypically requires 2868 ends. However, conventional equipment forforming a loom beam does not allow for all of these ends to betransferred from bobbins to a single beam in one operation. Therefore,multiple beams comprising a fraction of the number of required ends,typically referred to as “section beams,” can be produced and thereaftercombined to form the loom beam. In a manner similar to a loom beam, asection beam can include a cylindrical core comprising a plurality ofessentially parallel warp yarns wound thereabout. While it will berecognized by one skilled in the art that the section beam can compriseany number of warp yarns required to form the final loom beam, generallythe number of ends contained on a section beam is limited by thecapacity of the warping creel. For a 7781 style fabric, four sectionbeams of 717 ends each of DE75 yarn are typically provided and whencombined offer the required 2868 ends for the warp sheet, as discussedabove.

Composites of the present invention can be prepared by any suitablemethod known to one of ordinary skill in the art, such as but notlimited to vacuum assisted resin infusion molding, extrusioncompounding, compression molding, resin transfer molding, filamentwinding, prepreg/autoclave curing, and pultrusion. Composites of thepresent invention can be prepared using such molding techniques as knownto those of ordinary skill in the art. In particular, embodiments ofcomposites of the present invention that incorporate woven fiber glassfabrics can be prepared using techniques known to those of skill in theart for preparation of such composites.

As an example, some composites of the present invention can be madeusing vacuum assisted compression molding, which technique is well-knownto those of skill in the art and described briefly below. As known tothose of skill in the art, with vacuum assisted compression molding, astack of pre-impregnated glass fabrics is placed within a press platen.In some embodiments of the present invention, the stack ofpre-impregnated glass fabrics can include one or more fabrics of thepresent invention as described herein that have been cut to a desiredsize and shape. Upon completion of the stacking operation for thecorresponding number of layers, the press is closed and the platens areconnected to a vacuum pump so that the upper platen compresses on thestack of fabrics until the desired pressure is achieved. The vacuum aidsin the evacuation of entrapped air within the stack and provides for areduced void content in the molded laminate. Following connection of theplatens to a vacuum pump, the temperature of the platens is thenincreased to accelerate the conversion rate of the resin (e.g., athermosetting resin) to a predetermined temperature setting particularto the resin utilized, and kept at that temperature and pressure settinguntil the laminate reaches full cure. At this point, the heat is turnedoff and the platens are cooled by water circulation until they reachroom temperature. The platens can then be opened, and the moldedlaminate can be removed from the press.

As another example, some composites of the present invention can be madeusing vacuum assisted resin infusion technology, as further describedherein. A stack of glass fiber fabrics of the present invention may becut to a desired size and placed on a silicone release treated glasstable. The stack may then be covered with a peel ply, fitted with a flowenhancing media, and vacuum bagged using nylon bagging film. Next, theso-called “lay up” may be subjected to a vacuum pressure of about 27inches Hg. Separately, the polymeric resin that is to be reinforced withthe fiber glass fabrics can be prepared using techniques known to thoseof skill in the art for that particular resin. For example, for somepolymeric resins, an appropriate resin (e.g., an amine-curable epoxyresin) may be mixed with an appropriate curing agent (e.g., an amine foran amine-curable epoxy resin) in the proportions recommended by theresin manufacturer or otherwise known to a person of ordinary skill inthe art. The combined resin may then be degassed in a vacuum chamber for30 minutes and infused through the fabric preform until substantiallycomplete wet out of the fabric stack is achieved. At this point, thetable may be covered with heated blankets (set to a temperature of about45-50° C.) for 24 hours. The resulting rigid composites may then bede-molded and post cured at about 250° F. for 4 hours in a programmableconvection oven. As is known to persons of ordinary skill in the art,however, various parameters such as degassing time, heating time, andpost curing conditions may vary based on the specific resin system used,and persons of ordinary skill in the art understand how to select suchparameters based on a particular resin system.

Prepregs of the present invention can be prepared by any suitable meansknown to one of ordinary skill in the art, such as but not limited topassing fiber glass strands, rovings, or fabrics through a resin bath;using a solvent-based resin; or using a resin film.

As noted above, composites of the present invention can comprise apolymeric resin, in some embodiments. A variety of polymeric resins canbe used. Polymeric resins that are known to be useful in reinforcementapplications can be particularly useful in some embodiments. In someembodiments, the polymeric resin can comprise a thermoset resin.Thermoset resin systems useful in some embodiments of the presentinvention can include but are not limited to epoxy resin systems,phenolic based resins, polyesters, vinyl esters, thermosetpolyurethanes, polydicyclopentadiene (pDCPD) resins, cyanate esters, andbis-maleimides. In some embodiments, the polymeric resin can comprise anepoxy resin. In other embodiments, the polymeric resin can comprise athermoplastic resin. Thermoplastic polymers useful in some embodimentsof the present invention include but are not limited to polyethylene,polypropylene, polyamides (including Nylon), polybutylene terephthalate,polycarbonate, thermoplastic polyurethanes (TPU), polyphenylenesulfides, and polyether ether keteone (PEEK). Non-limiting examples ofcommercially available polymeric resins useful in some embodiments ofthe present invention include EPIKOTE Resin MGS® RIMR 135 epoxy withEpikure MGS RIMH 1366 curing agent (available from Momentive SpecialtyChemicals Inc. of Columbus, Ohio), Applied Poleramic MMFCS2 epoxy(available from Applied Poleramic, Inc., Benicia, Calif.), and EP255modified epoxy (available from Barrday Composite Solutions, Millbury,Mass.).

The invention will be illustrated through the following series ofspecific embodiments. However, it will be understood by one of skill inthe art that many other embodiments are contemplated by the principlesof the invention.

Examples

Table 1 provides a plurality of fiberizable glass compositions accordingto various embodiments of the present invention as well as data relatingto various properties of such compositions. Examples 1, 20, 21, 25, 62,and 77 are comparative examples, while the remaining examples representvarious embodiments of the present invention.

The glasses in these examples were made by melting mixtures ofcommercial and reagent grade chemicals (reagent grade chemicals wereused only for the rare earth oxides) in powder form in 10% Rh/Ptcrucibles at the temperatures between 1500° C. and 1550° C. (2732°F.-2822° F.) for four hours. Each batch was about 1000 grams. After the4 hour melting period, the molten glass was poured onto a steel platefor quenching. Volatile species, such as fluoride and alkali oxides,were not adjusted in the batches for their emission loss because oftheir low concentrations in the glasses. The compositions in theExamples represent as-batched compositions. Commercial ingredients wereused in preparing the glasses. In the batch calculation, special rawmaterial retention factors were considered to calculate the oxides ineach glass. The retention factors are based on years of glass batchmelting and oxides yield in the glass as measured. Hence, the as-batchedcompositions illustrated in the examples are considered to be close tothe measured compositions.

Melt Properties

Melt viscosity as a function of temperature and liquidus temperature wasdetermined by using ASTM Test Method C965 “Standard Practice forMeasuring Viscosity of Glass Above the Softening Point,” and C829“Standard Practices for Measurement of Liquidus Temperature of Glass bythe Gradient Furnace Method,” respectively.

Table 1 includes measured liquidus temperature (T_(L)), referencetemperature of forming (T_(F)) defined by melt viscosity of 1000 Poise,and reference temperature of melting (T_(m)) defined by viscosity of 100Poise, for the glass compositions. The difference between the formingtemperature and the liquidus temperature (ΔT) is also shown. Table 1also provides softening temperatures (T_(soft)), glass transitiontemperatures (T_(g)), and coefficients of thermal expansion (CTE) forsome of the compositions. Softening temperature (T_(soft)) values weremeasured in accordance with ASTM Test Method C338-93 “Standard TestMethod for Softening Point of Glass” (2008). Glass transitiontemperature (T_(g)) values were measured in accordance with ASTM TestMethod C336-71 “Annealing Point and Strain Point by Fiber Elongation.”Coefficient of thermal expansion (CTE) values were determined inaccordance with ASTM E228-11 “Standard Test Method for Linear ThermalExpansion of Solid Materials with a Push-Rod Dilatometer.”

Mechanical Properties

For the fiber tensile strength test, fiber samples from the glasscompositions were produced from a 10Rh/90Pt single tip fiber drawingunit. Approximately, 85 grams of cullet of a given composition was fedinto the bushing melting unit and conditioned at a temperature close orequal to the 100 Poise melt viscosity for two hours. The melt wassubsequently lowered to a temperature close or equal to the 1000 Poisemelt viscosity and stabilized for one hour prior to fiber drawing. Fiberdiameter was controlled to produce an approximately 10 m diameter fiberby controlling the speed of the fiber drawing winder. All fiber sampleswere captured in air without any contact with foreign objects. The fiberdrawing was completed in a room with a controlled humidity of between 40and 45% RH.

Fiber tensile strength was measured using a Kawabata KES-G1 (Kato TechCo. Ltd., Japan) tensile strength analyzer equipped with a Kawabata typeC load cell. Fiber samples were mounted on paper framing strips using aresin adhesive. A tensile force was applied to the fiber until failure,from which the fiber strength was determined based on the fiber diameterand breaking stress. The test was done at room temperature under thecontrolled humidity between 40-45% RH. The average values were computedbased on a sample size of 65-72 fibers for each composition. Table 1reports the average tensile strengths for fibers formed from some of thecompositions. Specific strengths were calculated by dividing the tensilestrength values (in N/m²) by the corresponding densities (in g/m³).

Young's modulus was also measured for certain glass compositions inTable 1 using the following technique. Approximately 50 grams of glasscullet having a composition corresponding to the appropriate exampleTable 1 was re-melted in a 90Pt/10Rh crucible for two hours at a meltingtemperature defined by 100 Poise. The crucible was subsequentlytransferred into a vertical tube, electrically heated furnace. Thefurnace temperature was preset at a fiber pulling temperature close orequal to a 1000 Poise melt viscosity. The glass was equilibrated at thetemperature for one hour before fiber drawing. The top of the fiberdrawing furnace had a cover with a center hole, above which awater-cooled copper coil was mounted to regulate the fiber cooling. Asilica rod was then manually dipped into the melt through the coolingcoil, and a fiber about 1-1.5 m long was drawn out and collected. Thediameter of the fiber ranged from 100μ at one end to 1000 μm at theother end.

Elastic moduli were determined using an ultrasonic acoustic pulsetechnique (Panatherm 5010 unit from Panametrics, Inc. of Waltham, Mass.)for the fibers drawn from the glass melts. Extensional wave reflectiontime was obtained using twenty micro-second duration, 200 kHz pulses.The sample length was measured and the respective extensional wavevelocity (V_(E)) was calculated. Fiber density (p) was measured using aMicromeritics AccuPyc 1330 pycnometer. About 20 measurements were madefor each composition and the average Young's modulus (E) was calculatedfrom the following formula:

E=V _(E) ²×ρ

The modulus tester uses a wave guide with a diameter of 1 mm, which setsthe fiber diameter at the contact side with the wave guide to be aboutthe same as the wave guide diameter. In other words, the end of thefiber having a diameter of 1000 μm was connected at the contact side ofthe wave guide. Fibers with various diameters were tested for Young'smodulus and the results show that a fiber diameter from 100 to 1000 μmdoes not affect fiber modulus. Specific modulus values were calculatedby dividing the Young's modulus values by the corresponding densities.

The values of “Fiber Failure strain (%)” (i.e., fiber elongation) inTable 1 were determined based on Hooke's law by dividing the tensilestrength values by the corresponding Young's modulus values (in the sameunits (e.g., all in MPa)), and multiplying by 100.

TABLE 1 1 2 3 4 5 6 SiO₂ 61.49 61.46 61.37 61.46 61.37 61.46 Al₂O₃ 15.2815.36 15.57 15.36 15.57 15.36 Fe₂O₃ 0.29 0.29 0.29 0.29 0.29 0.29 CaO15.43 13.18 12.51 13.18 12.51 13.18 MgO 6.12 6.26 6.21 6.26 6.21 6.26Na₂O 0.05 0.05 0.05 0.05 0.05 0.05 K₂O 0.09 0.09 0.09 0.09 0.09 0.09Sc₂O₃ 0.00 2.08 2.68 0.00 0.00 0.00 Y₂O₃ 0.00 0.00 0.00 2.08 2.68 0.00La₂O₃ 0.00 0.00 0.00 0.00 0.00 2.08 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00TiO₂ 0.50 0.50 0.51 0.50 0.51 0.50 Li₂O 0.74 0.72 0.72 0.72 0.72 0.72SO₃ 0.01 0.01 0.01 0.01 0.01 0.01 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00100.00 100.00 T_(L) (° C.) 1198 1197 1241 1197 1201 1199 T_(F) (° C.)1285 1288 1296 1306 1312 1300 ΔT (° C.) 87 91 55 109 111 101 T_(m) (°C.) 1489 1485 1495 1509 1513 1507 Fiber Density 2.62 2.62 2.62 2.62 2.632.63 (g/cm³) Fiber Modulus 89.2 91.0 91.6 90.6 90.2 88.0 (GPa) FiberStrength 3570 4108 4376 4264 4727 4321 (MPa) Fiber Failure 4.0 4.5 4.84.7 5.2 4.9 Strain (%) Specific Fiber 3.5 3.6 3.6 3.5 3.5 3.4 Modulus(×10⁶ m) Specific Fiber 139 160 171 166 184 168 Strength (×10³ m) 7 8 910 11 12 SiO₂ 61.37 61.46 61.37 59.74 59.73 59.73 Al₂O₃ 15.57 15.3615.57 16.00 17.46 17.46 Fe₂O₃ 0.29 0.29 0.29 0.27 0.29 0.29 CaO 12.5113.18 12.51 9.63 7.46 7.46 MgO 6.21 6.26 6.21 8.58 7.13 7.13 Na₂O 0.050.05 0.05 0.19 0.19 0.19 K₂O 0.09 0.09 0.09 0.09 0.09 0.09 Sc₂O₃ 0.000.00 0.00 4.24 6.34 4.44 Y₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 La₂O₃ 2.680.00 0.00 0.00 0.00 1.90 Nd₂O₃ 0.00 2.08 2.68 0.00 0.00 0.00 TiO₂ 0.510.50 0.51 0.63 0.69 0.69 Li₂O 0.72 0.72 0.72 0.61 0.61 0.61 SO₃ 0.010.01 0.01 0.02 0.02 0.02 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.000.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00 100.00T_(L) (° C.) 1198 1201 1201 1355 1376 T_(F) (° C.) 1309 1300 1308 13081349 1315 ΔT (° C.) 111 99 107 −47 −61 T_(m) (° C.) 1515 1506 1513 14911515 1507 Fiber Density 2.63 2.62 2.62 2.63 (g/cm³) Fiber Modulus 88.488.1 88.9 92.1 (GPa) Fiber Strength 4639 (MPa) Fiber Failure 5.3 Strain(%) Specific Fiber 3.4 3.4 3.5 3.6 Modulus (×10⁶ m) Specific Fiber 180Strength (×10³ m) 13 14 15 16 17 18 SiO₂ 59.73 59.74 59.73 59.73 59.7359.73 Al₂O₃ 17.46 16.00 17.46 17.46 17.46 17.46 Fe₂O₃ 0.29 0.27 0.290.29 0.29 0.29 CaO 7.46 9.63 7.46 7.46 7.46 7.46 MgO 7.13 8.58 7.13 7.137.13 7.13 Na₂O 0.19 0.19 0.19 0.19 0.19 0.19 K₂O 0.09 0.09 0.09 0.090.09 0.09 Sc₂O₃ 3.17 0.00 0.00 0.00 0.00 4.44 Y₂O₃ 0.00 4.24 6.34 4.443.17 0.00 La₂O₃ 3.17 0.00 0.00 1.90 3.17 0.00 Nd₂O₃ 0.00 0.00 0.00 0.000.00 0.00 TiO₂ 0.69 0.63 0.69 0.69 0.69 2.59 Li₂O 0.61 0.61 0.61 0.610.61 0.61 SO₃ 0.02 0.02 0.02 0.02 0.02 0.02 ZrO₂ 0.00 0.00 0.00 0.000.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00100.00 100.00 100.00 T_(L) (° C.) 1302 1194 1194 1193 1197 T_(F) (° C.)1317 1287 1327 1326 1330 ΔT (° C.) 15 93 133 133 133 T_(m) (° C.) 15121476 1515 1523 1532 Fiber Density 2.64 2.65 2.65 2.65 2.65 (g/cm³) FiberModulus 91.8 92.1 92.2 91.5 91.9 (GPa) Fiber Strength 5255 5181 5195(MPa) Fiber Failure 5.7 5.7 5.7 Strain (%) Specific Fiber 3.5 3.5 3.53.5 3.5 Modulus (×10⁶ m) Specific Fiber 202 199 200 Strength (×10³ m) 1920 21 22 23 24 SiO₂ 59.73 60.31 60.22 59.85 59.85 60.37 Al₂O₃ 17.4615.62 16.28 15.58 15.58 14.48 Fe₂O₃ 0.29 0.23 0.28 0.27 0.27 0.25 CaO7.46 13.84 13.06 11.05 11.05 5.46 MgO 7.13 8.63 8.61 8.70 8.70 8.03 Na₂O0.19 0.06 0.06 0.20 0.20 0.18 K₂O 0.09 0.07 0.09 0.09 0.09 0.08 Sc₂O₃4.44 0.00 0.00 2.88 0.00 0.00 Y₂O₃ 0.00 0.00 0.00 0.00 2.88 0.00 La₂O₃0.00 0.00 0.00 0.00 0.00 9.87 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂0.69 0.45 0.64 0.61 0.61 0.57 Li₂O 0.61 0.78 0.75 0.76 0.76 0.70 SO₃0.02 0.02 0.02 0.02 0.02 0.01 ZrO₂ 1.90 0.00 0.00 0.00 0.00 0.00 B₂O₃TOTAL 100.00 100.00 100.00 100.00 100.00 100.00 T_(L) (° C.) 1211 12251240 1195 1260 T_(F) (° C.) 1251 1265 1264 1268 1320 ΔT (° C.) 40 40 2473 60 T_(m) (° C.) 1441 1457 1450 1458 1523 Fiber Density 2.62 2.62 2.642.64 2.70 (g/cm³) Fiber Modulus 90.2 90.5 92.4 91.1 89.5 (GPa) FiberStrength 4622 4739 4913 4759 4978 (MPa) Fiber Failure 5.13 5.2 5.3 5.25.6 Strain (%) Specific Fiber 3.51 3.5 3.6 3.5 3.4 Modulus (×10⁶ m)Specific Fiber 180 185 190 184 188 Strength (×10³ m) 25 26 27 28 29 30SiO₂ 59.54 59.73 59.77 62.85 54.20 59.94 Al₂O₃ 17.28 17.35 17.36 19.7815.20 15.66 Fe₂O₃ 0.30 0.29 0.28 0.32 0.26 0.25 CaO 9.68 4.99 0.69 2.776.41 13.03 MgO 11.28 11.25 11.20 7.00 6.73 7.80 Na₂O 1.12 1.12 1.12 2.400.03 0.03 K₂O 0.10 0.09 0.09 0.00 0.07 0.09 Sc₂O₃ 0.00 0.00 0.00 3.163.88 0.00 Y₂O₃ 0.00 0.00 0.00 0.00 0.00 1.99 La₂O₃ 0.00 4.49 8.78 0.003.88 0.00 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ 0.68 0.68 0.68 0.780.02 0.52 Li₂O 0.00 0.00 0.00 0.00 0.59 0.65 SO₃ 0.02 0.02 0.02 0.020.02 0.02 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.938.71 0 TOTAL 100.00 100.00 100.00 100.00 100.00 100.00 T_(L) (° C.) 12651268 1324 1344 1300 1211 T_(F) (° C.) 1285 1316 1361 1397 1414 1275 ΔT(° C.) 20 48 37 53 114 64 T_(m) (° C.) 1471 1508 1559 1613 1631 1466Fiber Density 2.61 2.64 2.67 2.51 2.53 2.64 (g/cm³) Fiber Modulus 90.090.5 90.1 87.1 85.9 90.4 (GPa) Fiber Strength 5105 5294 5445 5503 5492(MPa) Fiber Failure 5.7 5.9 6.0 6.3 6.4 Strain (%) Specific Fiber 3.53.5 3.4 3.5 3.5 3.5 Modulus (×10⁶ m) Specific Fiber 199.7 204.8 208.0223.4 221.8 Strength (×10³ m) 31 32 33 34 35 36 SiO₂ 59.94 59.94 60.8561.67 61.67 59.52 Al₂O₃ 15.66 15.66 15.90 16.33 16.33 17.24 Fe₂O₃ 0.250.25 0.25 0.26 0.26 0.27 CaO 13.03 13.03 13.23 6.01 6.01 6.35 MgO 7.807.80 7.92 10.26 10.26 10.85 Na₂O 0.03 0.03 0.03 0.16 0.16 0.17 K₂O 0.090.09 0.10 0.09 0.09 0.10 Sc₂O₃ 0.00 1.99 0.51 0.00 0.00 0.00 Y₂O₃ 0.000.00 0.00 4.21 0.00 4.44 La₂O₃ 1.99 0.00 0.00 0.00 4.21 0.00 Nd₂O₃ 0.000.00 0.00 0.00 0.00 0.00 TiO₂ 0.52 0.52 0.53 0.58 0.58 0.61 Li₂O 0.650.65 0.66 0.42 0.42 0.44 SO₃ 0.02 0.02 0.02 0.00 0.00 0.00 ZrO₂ 0.000.00 0.00 0.00 0.00 0.00 B₂O₃ 0 0 0 0 0 0 TOTAL 100.00 100.00 100.00100.00 100.00 100.00 T_(L) (° C.) 1209 1212 1213 1258 1247 1232 T_(F) (°C.) 1265 1263 1270 1329 1331 1300 ΔT (° C.) 56 51 57 71 84 68 T_(m) (°C.) 1458 1451 1466 1529 1535 1489 Fiber Density 2.64 2.64 2.62 2.62 2.65(g/cm³) Fiber Modulus 90.6 90.3 92.2 90.9 94.1 (GPa) Fiber Strength 5224(MPa) Fiber Failure 5.6 Strain (%) Specific Fiber 3.5 3.5 3.6 3.5 3.6Modulus (×10⁶ m) Specific Fiber 201 Strength (×10³ m) 37 38 39 40 41 42SiO₂ 59.52 59.00 59.52 60.36 59.84 61.69 Al₂O₃ 17.24 17.25 17.40 17.6518.14 21.64 Fe₂O₃ 0.27 0.29 0.29 0.29 0.30 0.34 CaO 6.35 6.18 5.37 4.053.57 1.01 MgO 10.85 10.65 10.73 10.86 11.85 10.12 Na₂O 0.17 0.02 0.020.02 0.02 0.02 K₂O 0.10 0.09 0.09 0.09 0.09 0.11 Sc₂O₃ 0.00 0.00 0.000.00 0.00 0.00 Y₂O₃ 0.00 5.84 5.90 5.98 5.47 4.21 La₂O₃ 4.44 0.00 0.000.00 0.00 0.00 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ 0.61 0.68 0.680.69 0.71 0.85 Li₂O 0.44 0.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.000.00 0.00 0.00 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.000.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00 100.00 T_(L) (°C.) 1237 1276 1297 1336 1316 T_(F) (° C.) 1302 1315 1324 1340 1332 1392ΔT (° C.) 65 39 27 4 16 T_(m) (° C.) 1496 1500 1509 1529 1518 1599T_(soft)(° C.) 951 958 978 962 995 CTE (10⁻⁶/° C.) 3.1 Fiber Density2.66 2.63 2.66 2.65 2.65 2.58 (g/cm³) Fiber Modulus 92.8 92.8 93.2 94.193.6 92.4 (GPa) Fiber Strength 5076 (MPa) Fiber Failure 5.5 Strain (%)Specific Fiber 3.6 3.6 3.6 3.6 3.6 3.6 Modulus (×10⁶ m) Specific Fiber197 Strength (×10³ m) 43 44 45 46 47 48 SiO₂ 61.69 60.82 60.82 59.4060.03 60.48 Al₂O₃ 21.64 21.34 21.34 17.25 17.40 17.67 Fe₂O₃ 0.34 0.340.34 0.25 0.26 0.26 CaO 1.01 0.99 0.99 5.78 5.93 4.95 MgO 10.12 9.989.98 10.78 10.83 10.64 Na₂O 0.02 0.02 0.02 0.05 0.04 0.04 K₂O 0.11 0.110.11 0.10 0.10 0.10 Sc₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Y₂O₃ 0.00 5.560.00 4.79 4.03 4.34 La₂O₃ 4.21 0.00 5.56 0.00 0.00 0.00 Nd₂O₃ 0.00 0.000.00 0.00 0.00 0.00 TiO₂ 0.85 0.84 0.84 0.52 0.57 0.56 Li₂O 0.00 0.000.00 1.06 0.81 0.95 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 ZrO₂ 0.00 0.000.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00100.00 100.00 100.00 100.00 100.00 T_(L) (° C.) 1235 1237 1232 T_(F) (°C.) 1401 1397 1390 1273 1289 1299 ΔT (° C.) 38 52 67 T_(soft)(° C.) 992993 990 T_(m) (° C.) 1603 1595 1589 1467 1484 1499 Fiber Density 2.582.60 2.61 2.65 2.64 2.63 (g/cm³) Fiber Modulus 91.6 92.7 92.0 94.7 93.893.1 (GPa) Fiber Strength 5307 5237 5357 (MPa) Fiber Failure 5.6 5.6 5.8Strain (%) Specific Fiber 3.6 3.6 3.6 3.6 3.6 3.6 Modulus (×10⁶ m)Specific Fiber 204 203 207 Strength (×10³ m) Dielectric Constant 5.695.82 5.87 @1 GHz Dissipation loss 0.0020 0.0018 0.0017 @ 1 GHz 49 50 5152 53 54 SiO₂ 59.90 56.85 54.76 57.72 60.07 59.40 Al₂O₃ 16.54 15.7015.12 16.67 17.56 17.25 Fe₂O₃ 0.24 0.23 0.22 0.22 0.22 0.25 CaO 5.385.10 4.92 4.63 4.65 5.78 MgO 11.55 10.96 10.56 9.94 9.97 10.78 Na₂O 0.050.04 0.04 0.06 0.07 0.05 K₂O 0.10 0.09 0.09 0.11 0.12 0.10 Sc₂O₃ 0.000.00 0.00 0.00 0.00 0.00 Y₂O₃ 4.71 9.56 12.89 8.67 4.88 2.40 La₂O₃ 0.000.00 0.00 0.00 0.00 2.40 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ 0.500.48 0.46 0.43 0.39 0.52 Li₂O 1.03 0.98 0.94 1.55 2.08 1.06 SO₃ 0.000.00 0.00 0.00 0.00 0.01 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.000.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00 100.01T_(L) (° C.) 1252 1223 1225 1201 1216 1240 T_(F) (° C.) 1273 1247 12321252 1262 1273 ΔT (° C.) 21 24 7 51 46 33 T_(m) (° C.) 1464 1427 14031441 1465 1467 Fiber Density 2.65 2.74 2.81 2.71 (g/cm³) Fiber Modulus93.8 96.4 97.6 95.3 (GPa) Fiber Strength 5013 (MPa) Fiber Failure 5.3Strain (%) Specific Fiber 3.6 3.6 3.5 3.6 Modulus (×10⁶ m) SpecificFiber 182 Strength (×10³ m) 55 56 57 58 59 60 SiO₂ 59.40 60.03 60.0360.16 60.16 59.43 Al₂O₃ 17.25 17.40 17.40 18.32 18.32 18.10 Fe₂O₃ 0.250.26 0.26 0.28 0.28 0.27 CaO 5.78 5.93 5.93 5.43 5.43 5.36 MgO 10.7810.83 10.83 10.19 10.19 10.07 Na₂O 0.05 0.04 0.04 0.04 0.04 0.04 K₂O0.10 0.10 0.10 0.11 0.11 0.10 Sc₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Y₂O₃0.00 2.02 0.00 4.09 0.00 0.00 La₂O₃ 4.79 2.02 4.03 0.00 4.09 5.25 Nd₂O₃0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ 0.52 0.57 0.57 0.61 0.61 0.60 Li₂O1.06 0.81 0.81 0.79 0.79 0.78 SO₃ 0.01 0.01 0.01 0.00 0.00 0.00 ZrO₂0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL100.00 100.01 100.00 100.00 100.00 100.00 T_(L) (° C.) 1245 1240 12451233 1233 1227 T_(F) (° C.) 1275 1288 1290 1305 1302 1298 ΔT (° C.) 3048 45 71 69 71 T_(m) (° C.) 1473 1483 1487 1503 1503 1495 Fiber Density2.64 2.64 2.63 2.63 2.65 (g/cm³) Fiber Modulus 93.1 92.9 92.8 91.4 91.6(GPa) Fiber Strength 5368 (MPa) Fiber Failure 5.8 Strain (%) SpecificFiber 3.60 3.6 Modulus (×10⁶ m) Specific Fiber 207 Strength (×10³ m) 6162 63 64 65 66 SiO₂ 59.99 60.51 60.39 60.20 59.60 58.69 Al₂O₃ 17.8615.46 15.43 15.39 15.23 15.00 Fe₂O₃ 0.27 0.26 0.26 0.26 0.25 0.25 CaO4.49 14.49 14.46 14.42 14.27 14.05 MgO 9.92 8.17 8.15 8.13 8.05 7.93Na₂O 0.04 0.03 0.03 0.03 0.03 0.03 K₂O 0.10 0.09 0.09 0.09 0.09 0.09Sc₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Y₂O₃ 0.00 0.00 0.20 0.50 1.50 3.00La₂O₃ 5.97 0.00 0.00 0.00 0.00 0.00 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00TiO₂ 0.59 0.55 0.54 0.54 0.54 0.53 Li₂O 0.77 0.43 0.43 0.43 0.43 0.42SO₃ 0.00 0.01 0.01 0.01 0.01 0.01 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 99.99 99.99 99.99 99.9999.99 T_(L) (° C.) 1240 1205 1208 1200 1202 1209 T_(F) (° C.) 1316 12731268 1271 1269 1256 ΔT (° C.) 76 68 60 71 67 47 T_(m) (° C.) 1518 14681462 1465 1459 1440 Fiber Density 2.65 2.63 (g/cm³) Fiber Modulus 91.889.5 (GPa) Fiber Strength (MPa) Fiber Failure Strain (%) Specific Fiber3.5 Modulus (×10⁶ m) Specific Fiber Strength (×10³ m) 67 68 69 70 71 72SiO₂ 58.08 57.48 56.27 60.39 60.20 59.60 Al₂O₃ 14.84 14.69 14.38 15.4315.39 15.23 Fe₂O₃ 0.25 0.24 0.24 0.26 0.26 0.25 CaO 13.91 13.76 13.4714.46 14.42 14.27 MgO 7.84 7.76 7.60 8.15 8.13 8.05 Na₂O 0.03 0.03 0.030.03 0.03 0.03 K₂O 0.09 0.09 0.09 0.09 0.09 0.09 Sc₂O₃ 0.00 0.00 0.000.00 0.00 0.00 Y₂O₃ 4.00 5.00 7.00 0.00 0.00 0.00 La₂O₃ 0.00 0.00 0.000.20 0.50 1.50 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ 0.52 0.52 0.510.54 0.54 0.54 Li₂O 0.42 0.41 0.40 0.43 0.43 0.43 SO₃ 0.01 0.01 0.010.01 0.01 0.01 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.000.00 0.00 0.00 TOTAL 99.99 100.00 100.00 99.99 99.99 99.99 T_(L) (° C.)1206 1208 1212 1207 1205 1204 T_(F) (° C.) 1260 1255 1244 1265 1265 1259ΔT (° C.) 54 47 32 58 60 55 T_(m) (° C.) 1444 1463 1480 1456 1457 1447Fiber Density (g/cm³) Fiber Modulus (GPa) Fiber Strength (MPa) FiberFailure Strain (%) Specific Fiber Modulus (×10⁶ m) Specific FiberStrength (×10³ m) 73 74 75 76 77 78 79 80 SiO₂ 58.69 58.08 57.48 56.2760.72 60.81 58.91 58.91 Al₂O₃ 15.00 14.84 14.69 14.38 15.57 13.01 16.9516.95 Fe₂O₃ 0.25 0.25 0.24 0.24 0.27 0.23 0.25 0.25 CaO 14.05 13.9113.76 13.47 22.52 19.17 4.35 4.35 MgO 7.93 7.84 7.76 7.60 0.19 0.1610.49 10.49 Na₂O 0.03 0.03 0.03 0.03 0.01 0.01 0.04 0.04 K₂O 0.09 0.090.09 0.09 0.08 0.07 0.10 0.10 Sc₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 Y₂O₃ 0.00 0.00 0.00 0.00 0.00 6.01 3.98 0.00 La₂O₃ 3.00 4.00 5.007.00 0.00 0.00 0.00 3.98 Nd₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00TiO₂ 0.53 0.52 0.52 0.51 0.63 0.53 2.09 2.09 Li₂O 0.42 0.42 0.41 0.400.00 0.00 0.78 0.78 SO₃ 0.01 0.01 0.01 0.01 0.00 0.00 0.00 0.00 ZrO₂0.00 0.00 0.00 0.00 0.00 0.00 2.05 2.05 B₂O₃ 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 TOTAL 99.99 99.99 100.00 100.00 100.00 100.00 100.00100.00 T_(L) (° C.) 1202 1199 1196 1231 1272 T_(F) (° C.) 1253 1248 12451325 1346 1297 1298 ΔT (° C.) 51 49 49 94 74 T_(m) (° C.) 1440 1432 14271528 1543 1491 1496 T_(soft)(° C.) 943 962 912 904 T_(g) (° C.) 722 716CTE (10⁻⁶/° C.) 4.11 4.13 Fiber Density 2.62 2.68 2.66 2.66 (g/cm³)Fiber Modulus 82.0 83.7 93.8 92.4 (GPa) Fiber Strength 3948 4029 (MPa)Fiber Failure 4.8 4.8 Strain (%) Specific Fiber 3.2 3.2 3.6 3.5 Modulus(×10⁶ m) Specific Fiber 154 153 Strength (×10³ m) 81 82 83 84 85 86 8788 89 SiO₂ 61.43 59.81 59.04 58.66 57.41 58.17 54.56 56.41 51.18 Al₂O₃15.14 14.74 14.55 14.45 14.15 14.33 13.44 13.90 12.61 Fe₂O₃ 0.26 0.260.25 0.25 0.25 0.25 0.23 0.24 0.22 CaO 14.70 12.52 11.46 10.95 10.7212.17 9.36 11.80 8.78 MgO 7.98 7.77 7.67 7.62 7.45 7.55 7.08 7.32 6.65Na₂O 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 K₂O 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 Sc₂O₃ 0.00 4.43 6.56 7.60 9.56 0.00 0.000.00 0.00 Y₂O₃ 0.00 0.00 0.00 0.00 0.00 7.05 14.88 0.00 0.00 La₂O₃ 0.000.00 0.00 0.00 0.00 0.00 0.00 9.87 20.15 Nd₂O₃ 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 TiO₂ 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Li₂O 0.49 0.48 0.47 0.47 0.46 0.47 0.44 0.45 0.41 SO₃ 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 ZrO₂ 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.0100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 T_(L) (° C.) 1199 13371434 1462 1516 1204 1294 1184 1158 T_(F) (° C.) 1296 1285 1284 1307 13481280 1260 1266 1237 ΔT (° C.) 97 −52 −150 −155 −168 76 −34 82 79 T_(m)(° C.) 1495 1471 1458 1447 1449 1464 1426 1450 1406 T_(soft) (° C.) 898917 920 925 931 911 922 899 903 T_(g) (° C.) 717 740 750 759 757 734 748721 729 CTE (10⁻⁶/° C.) 4.63 4.61 4.54 4.54 4.44 Fiber Density 2.60 2.642.70 2.78 (g/cm³) Fiber Modulus 89.4 92.4 91.6 90.8 (GPa) Fiber Strength(MPa) Fiber Failure Strain (%) Specific Fiber 3.5 3.6 3.5 3.3 Modulus(×10⁶ m) Specific Fiber Strength (×10³ m) 90 91 92 93 SiO₂ 63.08 65.0365.03 64.49 Al₂O₃ 16.16 15.35 15.35 14.61 Fe₂O₃ 0.24 0.23 0.23 0.19 CaO4.40 3.37 3.37 3.00 MgO 10.63 10.86 10.86 9.67 Na₂O 0.04 0.04 0.04 0.03K₂O 0.09 0.09 0.09 0.08 Sc₂O₃ 0.00 0.00 0.00 0.00 Y₂O₃ 0.00 0.00 3.680.00 La₂O₃ 4.04 3.68 0.00 4.33 Nd₂O₃ 0.00 0.00 0.00 0.00 TiO₂ 0.52 0.470.47 0.39 Li₂O 0.79 0.89 0.89 0.79 SO₃ 0.00 0.00 0.00 0.00 ZrO₂ 0.000.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 P₂O₅ 0.00 0.00 0.00 2.42 TOTAL100.0 100.0 100.0 100.0 T_(L) (° C.) 1267 T_(F) (° C.) 1332 1355 13501396 ΔT (° C.) 65 T_(m)(° C.) 1542 1572 1562 1619 Fiber Density 2.60(g/cm³) Fiber Modulus 91.4 (GPa) Fiber Strength (MPa) Fiber FailureStrain (%) Specific Fiber 3.6 Modulus (×10⁶ m) Specific Fiber Strength(×10³ m)

Certain of these data were plotted in FIGS. 1-4. FIG. 1 is a chartshowing Young's modulus values relative to the amount of rare earthoxides (RE₂O₃) for the glass compositions in Examples 1-17, 22, and 23.FIG. 2 is a chart showing pristine fiber tensile strength valuesrelative to the amount of rare earth oxides (RE₂O₃) for the glasscompositions in Examples 1-17, 22, and 23. FIG. 3 is a chart showingsoftening and glass transition temperatures relative to the amount ofrare earth oxides (RE₂O₃) for the glass compositions of Examples 81-89.FIG. 4 is a chart showing linear coefficient of thermal expansionrelative to the amount of scandium oxide (Sc₂O₃) for the glasscompositions of Examples 81-89.

Table 2 provides a plurality of fiberizable glass compositions accordingto various embodiments of the present invention as well as data relatingto various properties of such compositions. The embodiments of Table 2were produced in the same manner as those in Table 1. The meltproperties and mechanical properties of the embodiments of Table 2 weredetermined in the same manner as for those in Table 1.

TABLE 2 94 95 96 97 98 99 SiO₂ 61.42 60.85 60.07 61.02 61.28 60.18 Al₂O₃17.85 17.62 17.52 17.80 17.87 16.77 CaO 5.42 5.64 5.92 6.00 6.01 7.18MgO 8.81 9.18 9.63 8.22 6.29 8.05 BaO 0.00 0.00 0.00 0.00 0.00 0.00 SrO0.00 0.00 0.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O0.04 0.05 0.04 0.04 0.04 0.04 K₂O 0.11 0.10 0.10 0.11 0.11 0.10 Li₂O0.96 1.00 0.91 0.93 0.93 1.01 Fe₂O₃ 0.37 0.37 0.37 0.38 0.38 0.37 TiO₂0.56 0.55 0.56 0.57 2.13 1.36 Y₂O₃ 4.45 4.64 4.87 4.94 4.96 4.93 La₂O₃0.00 0.00 0.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO0.00 0.00 0.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃0.00 0.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL100.00 100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 3.44 3.45 3.43 3.433.43 3.59 MgO/CaO 1.63 1.63 1.63 1.37 1.05 1.12 CaO + MgO + 14.23 14.8215.55 14.21 12.29 15.24 BaO + SrO BaO + SrO + ZnO 0.00 0.00 0.00 0.000.00 0.00 T_(L) (° C) 1188 1188 1200 1185 1208 1154 T_(F) (° C) 13191307 1297 1320 1338 1294 ΔT (° C) 131 119 97 135 130 140 T_(m) (° C)1522 1508 1494 1521 1549 1493 Fiber Density 2.61 2.62 2.63 2.62 2.61(g/cm³) Fiber Modulus 92.3 92.0 92.8 91.9 90.0 (GPa) Fiber Strength 54905492 5340 5467 (MPa) Fiber Failure 5.9 6.0 5.8 5.9 Strain (%) SpecificFiber 3.6 3.6 3.6 3.6 3.5 Modulus (×10⁶ m) Specific Fiber 215.0 214.2207.0 213.2 0.0 Strength (×10³ m) 100 101 102 103 104 105 SiO₂ 61.2860.18 60.83 60.12 59.78 61.00 Al₂O₃ 17.87 16.77 15.23 17.84 17.99 16.75CaO 6.01 7.18 7.90 5.88 5.93 4.67 MgO 6.29 8.05 8.86 9.47 9.55 10.20 BaO0.00 0.00 0.00 0.00 0.00 0.00 SrO 0.00 0.00 0.00 0.00 0.00 2.46 ZnO 0.000.00 0.00 0.00 0.00 0.00 Na₂O 0.04 0.04 0.04 0.04 0.04 0.04 K₂O 0.110.10 0.09 0.10 0.10 0.10 Li₂O 0.93 1.01 0.77 0.77 0.78 0.72 Fe₂O₃ 0.380.37 0.37 0.39 0.40 0.25 TiO₂ 0.56 0.56 1.41 0.59 0.59 0.55 Y₂O₃ 4.964.93 4.50 4.80 4.84 3.25 La₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Cu₂O 1.570.80 0.00 0.00 0.00 0.00 MnO 0.00 0.00 0.00 0.00 0.00 0.00 MnO₂ 0.000.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 SO₃ 0.000.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00 100.00SiO₂/Al₂O₃ 3.43 3.59 3.99 3.37 3.32 3.64 MgO/CaO 1.05 1.12 1.12 1.611.61 2.19 CaO + MgO + 12.29 15.24 16.76 15.35 15.48 17.33 BaO + SrOBaO + SrO + ZnO 0.00 0.00 0.00 0.00 0.00 2.46 T_(L) (° C) 1153 1167 12191226 1201 1235 T_(F) (° C) 1336 1291 1289 1307 1299 1320 ΔT (° C) 183124 70 81 98 85 T_(m) (° C) 1547 1447 1491 1501 1493 1519 Fiber Density2.62 2.64 2.63 (g/cm³) Fiber Modulus 91.1 91.8 92.6 (GPa) Fiber Strength5321 5243 5583 (MPa) Fiber Failure 5.8 5.7 6.03 Strain (%) SpecificFiber 3.5 3.5 3.6 Modulus (×10⁶ m) Specific Fiber 207.0 202.5 216.6Strength (×10³ m) 106 107 108 109 110 111 SiO₂ 60.48 62.01 64.00 66.0065.00 63.00 Al₂O₃ 17.67 16.98 16.09 15.21 15.16 16.02 CaO 4.95 4.76 4.514.26 3.62 3.83 MgO 10.64 10.22 9.68 9.14 10.83 11.45 BaO 0.00 0.00 0.000.00 0.00 0.00 SrO 0.00 0.00 0.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.000.00 0.00 Na₂O 0.04 0.04 0.04 0.04 0.04 0.04 K₂O 0.10 0.10 0.09 0.090.09 0.09 Li₂O 0.95 0.90 0.86 0.80 0.80 0.85 Fe₂O₃ 0.26 0.25 0.24 0.230.23 0.24 TiO₂ 0.56 0.54 0.51 0.48 0.48 0.50 Y₂O₃ 4.33 4.20 3.98 3.753.74 3.96 La₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.000.00 0.00 MnO 0.00 0.00 0.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.000.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.004 0.00 0.000.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃3.42 3.65 3.98 4.34 4.29 3.93 MgO/CaO 2.15 2.15 2.15 2.15 2.99 2.99CaO + MgO + 15.60 14.99 14.19 13.40 14.46 15.29 BaO + SrO BaO + SrO +ZnO 0.00 0.00 0.00 0.00 0.00 0.00 T_(L) (° C) 1232 1234 1282 1332 13291288 T_(F) (° C) 1299 1321 1348 1383 1358 1329 ΔT (° C) 67 87 66 51 2941 T_(m) (° C) 1499 1522 1558 1601 1567 1532 Fiber Density 2.63 2.612.58 2.56 2.57 2.60 (g/cm³) Fiber Modulus 93.1 92.6 91.7 89.2 90.8 92.7(GPa) Fiber Strength 5357.0 5462 5456 (MPa) Fiber Failure 5.8 5.9 6.0Strain (%) Specific Fiber 3.54 3.55 3.55 3.49 3.53 3.57 Modulus (×10⁶ m)Specific Fiber 203.8 209.5 211.5 Strength (×10³ m) 112 113 114 115 116117 SiO₂ 61.00 60.43 62.00 64.00 65.00 63.50 Al₂O₃ 16.88 17.70 17.0016.11 15.67 14.91 CaO 4.04 0.10 0.10 0.09 0.09 5.11 MgO 12.08 10.6510.22 9.68 9.41 10.11 BaO 0.00 0.00 0.00 0.00 0.00 0.00 SrO 0.00 0.000.00 0.00 0.00 0.00 ZnO 0.00 4.90 4.70 4.46 4.33 0.00 Na₂O 0.04 0.040.04 0.04 0.04 0.03 K₂O 0.10 0.10 0.10 0.09 0.09 0.08 Li₂O 0.91 0.950.91 0.86 0.84 0.50 Fe₂O₃ 0.25 0.25 0.24 0.23 0.23 0.24 TiO₂ 0.52 0.560.54 0.51 0.49 0.50 Y₂O₃ 4.17 4.30 4.14 3.92 3.80 5.01 La₂O₃ 0.00 0.000.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO 0.00 0.000.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.000.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 3.61 3.41 3.65 3.97 4.154.26 MgO/CaO 2.99 102.58 102.58 102.58 102.58 1.98 CaO + MgO + 16.1310.76 10.33 9.78 9.51 15.23 BaO + SrO BaO + SrO + ZnO 0.00 4.90 4.704.46 4.33 0.00 T_(L) (° C) 1242 1296 1321 1361 1378 1330 T_(F) (° C)1301 1315 1338 1362 1381 1360 ΔT (° C) 59 19 17 1 3 30 T_(m) (° C) 14961516 1546 1577 1600 1572 Fiber Density 2.62 (g/cm³) Fiber Modulus 94.8(GPa) Fiber Strength 5395 (MPa) Fiber Failure 5.7 Strain (%) SpecificFiber 3.62 Modulus (×10⁶ m) Specific Fiber 206.1 Strength (×10³ m) 118119 120 121 122 123 SiO₂ 64.01 62.50 64.01 62.49 64.00 62.51 Al₂O₃ 13.5716.93 17.34 16.70 17.37 16.93 CaO 5.34 2.41 0.09 1.30 0.09 4.70 MgO10.55 9.10 9.28 10.49 9.28 10.20 BaO 0.00 0.00 0.00 3.05 3.20 0.00 SrO0.00 3.04 3.23 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O0.03 0.03 0.03 0.03 0.03 0.03 K₂O 0.08 0.09 0.09 0.09 0.09 0.10 Li₂O0.51 0.55 0.57 0.53 0.56 0.60 Fe₂O₃ 0.22 0.26 0.26 0.25 0.26 0.26 TiO₂0.46 0.58 0.60 0.58 0.60 0.58 Y₂O₃ 5.23 4.51 4.51 4.49 4.51 4.09 La₂O₃0.00 0.00 0.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO0.00 0.00 0.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃0.00 0.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL100.00 100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 4.72 3.69 3.69 3.743.68 3.69 MgO/CaO 1.98 3.78 104.76 8.09 104.83 2.17 CaO + MgO + 15.9014.55 12.60 14.84 12.57 14.90 BaO + SrO BaO + SrO + ZnO 0.00 3.04 3.233.05 3.20 0.00 T_(L) (° C) 1352 1317 1348 1327 1347 1290 T_(F) (° C)1347 1381 1415 1378 1428 1350 ΔT (° C) −5 64 67 51 81 60 T_(m) (° C)1552 1590 1633 1587 1648 1553 Fiber Density 2.611 2.5728 (g/cm³) FiberModulus 90.5 89.99 (GPa) Fiber Strength (MPa) Fiber Failure Strain (%)Specific Fiber 3.46 3.50 Modulus (×10⁶ m) Specific Fiber Strength (×10³m) 124 125 126 127 128 129 SiO₂ 62.25 62.39 62.31 62.01 64.00 66.00Al₂O₃ 16.72 16.63 16.85 16.98 16.09 15.21 CaO 4.78 5.01 4.97 4.76 4.514.26 MgO 10.20 10.01 9.93 10.22 9.68 9.14 BaO 0.00 0.00 0.00 0.00 0.000.00 SrO 0.00 0.00 0.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00 0.00 0.00Na₂O 0.03 0.03 0.03 0.04 0.04 0.04 K₂O 0.09 0.09 0.09 0.10 0.09 0.09Li₂O 0.60 0.50 0.50 0.90 0.86 0.80 Fe₂O₃ 0.26 0.26 0.26 0.25 0.24 0.23TiO₂ 0.57 0.58 0.59 0.54 0.50 0.48 Y₂O₃ 4.49 4.50 4.46 0.00 0.00 0.00La₂O₃ 0.00 0.00 0.00 4.20 3.98 3.75 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00MnO 0.00 0.00 0.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00TOTAL 100.00 100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 3.72 3.753.70 3.65 3.98 4.34 MgO/CaO 2.13 2.00 2.00 2.15 2.15 2.15 CaO + MgO +14.98 15.01 14.90 14.99 14.19 13.40 BaO + SrO BaO + SrO + ZnO 0.00 0.000.00 0.00 0.00 0.00 T_(L) (° C) 1288 1292 1292 1234 1283 1338 T_(F) (°C) 1339 1348 1346 1321 1363 1386 ΔT (° C) 51 56 54 87 80 48 T_(m) (° C)1539 1550 1548 1527 1579 1608 Fiber Density (g/cm³) Fiber Modulus (GPa)Fiber Strength 5365 (MPa) Fiber Failure Strain (%) Specific FiberModulus (×10⁶ m) Specific Fiber Strength (×10³ m) 130 131 132 133 134135 SiO₂ 65.00 63.00 61.00 60.43 62.00 64.00 Al₂O₃ 15.16 16.02 16.8817.70 17.00 16.11 CaO 3.62 3.83 4.04 0.10 0.10 0.09 MgO 10.83 11.4512.08 10.65 10.22 9.68 BaO 0.00 0.00 0.00 0.00 0.00 0.00 SrO 0.00 0.000.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 4.90 4.70 4.46 Na₂O 0.04 0.040.04 0.04 0.04 0.04 K₂O 0.09 0.09 0.10 0.10 0.10 0.09 Li₂O 0.80 0.850.90 0.95 0.90 0.86 Fe₂O₃ 0.23 0.24 0.25 0.25 0.24 0.23 TiO₂ 0.48 0.500.52 0.56 0.54 0.50 Y₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 La₂O₃ 3.74 3.964.18 4.31 4.14 3.92 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO 0.00 0.000.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.000.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 4.29 3.93 3.61 3.41 3.653.97 MgO/CaO 2.99 2.99 2.99 102.58 102.58 102.58 CaO + MgO + 14.46 15.2916.13 10.76 10.33 9.78 BaO + SrO BaO + SrO + ZnO 0.00 0.00 0.00 4.904.70 4.46 T_(L) (° C) 1313 1263 1259 1307 1315 1352 T_(F) (° C) 13591325 1298 1324 1348 1380 ΔT (° C) 46 62 39 17 33 28 T_(m) (° C) 15741532 1496 1530 1563 1606 Fiber Density (g/cm³) Fiber Modulus (GPa) FiberStrength 5355 (MPa) Fiber Failure Strain (%) Specific Fiber Modulus(×10⁶ m) Specific Fiber Strength (×10³ m) 136 137 138 139 140 141 SiO₂65.00 61.42 61.02 60.85 62.50 62.49 Al₂O₃ 15.67 17.85 17.80 17.62 16.9316.70 CaO 0.09 5.42 6.00 5.64 2.41 1.30 MgO 9.41 8.81 8.22 9.18 9.1010.49 BaO 0.00 0.00 0.00 0.00 0.00 3.05 SrO 0.00 0.00 0.00 0.00 3.040.00 ZnO 4.33 0.00 0.00 0.00 0.00 0.00 Na₂O 0.04 0.04 0.04 0.05 0.030.03 K₂O 0.09 0.11 0.11 0.10 0.09 0.09 Li₂O 0.84 0.96 0.93 1.00 0.550.53 Fe₂O₃ 0.23 0.37 0.38 0.37 0.26 0.25 TiO₂ 0.49 0.56 0.57 0.55 0.580.58 Y₂O₃ 0.00 4.45 4.94 4.64 4.51 4.49 La₂O₃ 3.80 0.00 0.00 0.00 0.000.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO 0.00 0.00 0.00 0.00 0.000.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.000.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00100.00 100.00 SiO₂/Al₂O₃ 4.15 3.44 3.43 3.45 3.69 3.74 MgO/CaO 102.581.63 1.37 1.63 3.78 8.09 CaO + MgO + 9.51 14.23 14.21 14.82 14.55 14.84BaO + SrO BaO + SrO + ZnO 4.33 0.00 0.00 0.00 3.04 3.05 T_(L) (° C) 13711188 1185 1188 1317 1327 T_(F) (° C) 1398 1319 1320 1307 1381 1378 ΔT (°C) 27 131 135 119 64 51 T_(m) (° C) 1625 1522 1521 1508 1590 1587 FiberDensity 2.61 2.62 2.62 2.61 (g/cm³) Fiber Modulus 92.3 91.9 92.0 90.5(GPa) Fiber Strength 5490 5467 5492 (MPa) Fiber Failure 5.9 5.9 6.0Strain (%) Specific Fiber 3.6 3.6 3.6 3.46 Modulus (×10⁶ m) SpecificFiber 215.0 213.2 214.2 Strength (×10³ m) 142 143 144 145 146 147 SiO₂64.01 64.00 61.28 61.28 60.18 60.18 Al₂O₃ 17.34 17.37 17.87 17.87 16.7716.77 CaO 0.09 0.09 6.01 6.01 7.18 7.18 MgO 9.28 9.28 6.29 6.29 8.058.05 BaO 0.00 3.20 0.00 0.00 0.00 0.00 SrO 3.23 0.00 0.00 0.00 0.00 0.00ZnO 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O 0.03 0.03 0.04 0.04 0.04 0.04 K₂O0.09 0.09 0.11 0.11 0.10 0.10 Li₂O 0.57 0.56 0.93 0.93 1.01 1.01 Fe₂O₃0.26 0.26 0.38 0.38 0.37 0.37 TiO₂ 0.60 0.60 2.13 0.56 1.36 0.56 Y₂O₃4.51 4.51 4.96 4.96 4.93 4.93 La₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 Cu₂O0.00 0.00 0.00 1.57 0.00 0.80 MnO 0.00 0.00 0.00 0.00 0.00 0.00 MnO₂0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 0.00 0.00 SO₃0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 100.00100.00 SiO₂/Al₂O₃ 3.69 3.68 3.43 3.43 3.59 3.59 MgO/CaO 104.76 104.831.05 1.05 1.12 1.12 CaO + MgO + 12.60 12.57 12.29 12.29 15.24 15.24BaO + SrO BaO + SrO + ZnO 3.23 3.20 0.00 0.00 0.00 0.00 T_(L) (° C) 13481347 1208 1153 1154 1167 T_(F) (° C) 1415 1428 1338 1336 1294 1291 ΔT (°C) 67 81 130 183 140 124 T_(m) (° C) 1633 1648 1549 1547 1493 1447 FiberDensity 2.57 2.61 2.62 (g/cm³) Fiber Modulus 89.99 90.0 91.1 (GPa) FiberStrength 5321 (MPa) Fiber Failure 5.8 Strain (%) Specific Fiber 3.50 3.53.5 Modulus (×10⁶ m) Specific Fiber 0.0 207.0 Strength (×10³ m) 148 149150 151 152 153 SiO₂ 60.83 61.00 60.12 59.78 60.07 64.01 Al₂O₃ 15.2316.75 17.84 17.99 17.52 13.57 CaO 7.90 4.67 5.88 5.93 5.92 5.34 MgO 8.8610.20 9.47 9.55 9.63 10.55 BaO 0.00 0.00 0.00 0.00 0.00 0.00 SrO 0.002.46 0.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O 0.040.04 0.04 0.04 0.04 0.03 K₂O 0.09 0.10 0.10 0.10 0.10 0.08 Li₂O 0.770.72 0.77 0.78 0.91 0.51 Fe₂O₃ 0.37 0.25 0.39 0.40 0.37 0.22 TiO₂ 1.410.55 0.59 0.59 0.56 0.46 Y₂O₃ 4.50 3.25 4.80 4.84 4.87 5.23 La₂O₃ 0.000.00 0.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO 0.000.00 0.00 0.00 0.00 0.00 MnO₂ 0.00 0.00 0.00 0.00 0.00 0.00 B₂O₃ 0.000.00 0.00 0.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00100.00 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 3.99 3.64 3.37 3.32 3.434.72 MgO/CaO 1.12 2.19 1.61 1.61 1.63 1.98 CaO + MgO + 16.76 17.33 15.3515.48 15.55 15.90 BaO + SrO BaO + SrO + ZnO 0.00 2.46 0.00 0.00 0.000.00 T_(L) (° C) 1219 1235 1226 1201 1200 1352 T_(F) (° C) 1289 13201307 1299 1297 1347 ΔT (° C) 70 85 81 98 97 −5 T_(m) (° C) 1491 15191501 1493 1494 1552 Fiber Density 2.64 2.63 2.63 2.62 (g/cm³) FiberModulus 91.8 92.6 92.8 85.2 (GPa) Fiber Strength 5243 5583 5340 (MPa)Fiber Failure 5.7 6.03 5.8 Strain (%) Specific Fiber 3.5 3.6 3.6 Modulus(×10⁶ m) Specific Fiber 202.5 216.6 207.0 Strength (×10³ m) 154 155 156157 158 159 SiO₂ 60.61 58.73 59.81 62.19 64.78 63.74 Al₂O₃ 15.26 14.7815.06 15.66 16.31 16.05 CaO 7.01 4.75 0.06 0.03 0.03 0.03 MgO 5.49 5.296.07 2.38 2.48 2.44 BaO 0.00 0.00 0.00 0.00 0.00 0.00 SrO 0.00 0.00 0.000.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O 0.04 0.04 0.040.04 0.04 0.04 K₂O 0.09 0.09 0.08 0.09 0.09 0.09 Li₂O 0.83 0.81 0.820.86 0.89 0.88 Fe₂O₃ 0.22 0.21 0.21 0.21 0.22 0.22 TiO₂ 2.00 7.11 6.506.76 7.04 6.93 Y₂O₃ 3.89 3.77 3.84 4.00 0.00 1.61 La₂O₃ 0.00 0.00 0.000.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 0.00 0.00 MnO 0.00 0.00 0.000.00 0.00 0.00 MnO₂ 4.55 4.41 7.49 7.79 8.12 7.99 B₂O₃ 0.00 0.00 0.000.00 0.00 0.00 SO₃ 0.00 0.00 0.00 0.00 0.00 0.00 TOTAL 100.00 100.00100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 3.97 3.97 3.97 3.97 3.97 3.97MgO/CaO 0.78 1.11 99.34 86.24 86.24 86.24 CaO + MgO + 12.50 10.05 6.142.41 2.51 2.47 BaO + SrO BaO + SrO + ZnO 0.00 0.00 0.00 0.00 0.00 0.00T_(L) (° C) 1232 1350 1342 1356 1339 1347 T_(F) (° C) 1362 1341 13211405 1444 1428 ΔT (° C) 130 −9 −21 49 105 81 T_(m) (° C) 1600 1579 15381645 1694 1677 Fiber Density 2.62 2.63 2.58 2.50 2.53 (g/cm³) FiberModulus 85.4 88.9 85.4 82.9 83.9 (GPa) Fiber Strength (MPa) FiberFailure Strain (%) Specific Fiber Modulus (×10⁶ m) Specific FiberStrength (×10³ m) 160 161 162 163 SiO₂ 63.40 69.97 63.25 60.85 Al₂O₃14.65 16.98 22.00 15.16 CaO 0.03 2.11 0.06 1.52 MgO 2.78 3.82 6.77 0.05BaO 0.00 0.00 0.00 0.00 SrO 0.00 0.00 0.00 0.00 ZnO 0.00 0.00 0.00 0.00Na₂O 0.02 0.03 0.02 0.04 K₂O 0.07 0.09 0.11 0.09 Li₂O 0.00 0.54 0.000.79 Fe₂O₃ 0.23 0.25 0.34 0.21 TiO₂ 7.89 3.40 5.33 8.29 Y₂O₃ 1.83 0.940.00 5.07 La₂O₃ 0.00 0.00 0.00 0.00 Cu₂O 0.00 0.00 0.00 0.00 MnO 0.000.00 2.11 7.95 MnO₂ 9.11 1.86 0.00 0.00 B₂O₃ 0.00 0.00 0.00 0.00 SO₃0.00 0.00 0.00 0.00 TOTAL 100.00 100.00 100.00 100.00 SiO₂/Al₂O₃ 4.334.12 2.87 4.01 MgO/CaO 110.30 1.81 109.95 0.03 CaO + MgO + 2.81 5.946.83 1.56 BaO + SrO BaO + SrO + ZnO 0.00 0.00 0.00 0.00 T_(L) (° C) 14561387 1389 1392 T_(F) (° C) 1450 1547 1426 1385 ΔT (° C) −6 160 37 −7T_(m) (° C) 1684 1812 1646 1626 Fiber Density 2.44 2.55 (g/cm³) FiberModulus 83.3 83.9 (GPa) Fiber Strength (MPa) Fiber Failure Strain (%)Specific Fiber Modulus (×10⁶ m) Specific Fiber Strength (×10³ m)

Desirable characteristics that can be exhibited by various but notnecessarily all embodiments of the present invention can include, butare not limited to, the following: the provision of glass fibers, fiberglass strands, glass fiber fabrics, composites, and related productshaving a relatively low density; the provision of glass fibers, fiberglass strands, glass fiber fabrics, composites, and laminates having arelatively high tensile strength; the provision of glass fibers, fiberglass strands, glass fiber fabrics, composites, and related productshaving a relatively low density; the provision of glass fibers, fiberglass strands, glass fiber fabrics, composites, and laminates having arelatively high modulus; the provision of glass fibers, fiber glassstrands, glass fiber fabrics, composites, and laminates having arelatively high elongation; the provision of glass fibers, fiber glassstrands, glass fiber fabrics, prepregs, and other products useful forreinforcement applications; and others.

It is to be understood that the present description illustrates aspectsof the invention relevant to a clear understanding of the invention.Certain aspects of the invention that would be apparent to those ofordinary skill in the art and that, therefore, would not facilitate abetter understanding of the invention have not been presented in orderto simplify the present description. Although the present invention hasbeen described in connection with certain embodiments, the presentinvention is not limited to the particular embodiments disclosed, but isintended to cover modifications that are within the spirit and scope ofthe invention.

What is claimed is: 1-20. (canceled)
 21. A polymeric compositecomprising: a polymeric material; and at least one glass fiber in thepolymeric material, the at least one glass fiber comprising: SiO₂ fromabout 51 to about 70 weight percent; Al₂O₃ from about 12.5 to about 22weight percent; CaO from 0 to about 20 weight percent; MgO from 0 toabout 11 weight percent; Fe₂O₃ from about 0.2 to about 1 weight percent;RE₂O₃ about 0.05 or greater weight percent; BaO from 0 to about 4 weightpercent; SrO from 0 to about 4 weight percent; and ZnO from 0 to about5.5 weight percent;

wherein the sum of BaO+SrO+ZnO is greater than 2 weight percent.
 22. Thepolymeric composite of claim 21, wherein the sum of BaO+SrO+ZnO isgreater than 3 weight percent.
 23. The polymeric composite of claim 21,wherein BaO is present in an amount greater than 2 weight percent. 24.The polymeric composite of claim 21, wherein SrO is present in an amountgreater than 2 weight percent.
 25. The polymeric composite of claim 21,wherein ZnO is present in an amount greater than 2 weight percent. 26.The polymeric composite of claim 21, further comprising less than 1.5weight percent Na₂O+K₂O+Li₂O.
 27. The polymeric composite of claim 21,further comprising from 0 to about 1 weight percent B₂O₃.
 28. Apolymeric composite comprising: a polymeric material; and at least oneglass fiber in the polymeric material, the at least one glass fibercomprising: SiO₂ from about 51 to about 65 weight percent; Al₂O₃ fromabout 12.5 to about 22 weight percent; CaO from 0 to about 20 weightpercent; MgO from 0 to about 12 weight percent; Fe₂O₃ from about 0.2 toabout 1 weight percent; RE₂O₃ greater than 2 weight percent, whereinRE₂O₃ comprises La₂O₃ in an amount greater than 2 weight percent;

and at least one additional feature selected from the group consistingof: CaO is present in an amount less than 2 weight percent; a ratio ofMgO content to CaO content (MgO/CaO) less than 1; and a ratio of SiO₂content to Al₂O₃ content (SiO₂/Al₂O₃) greater than
 4. 29. The polymericcomposite of claim 28, wherein the fiber comprises La₂O₃ in an amountgreater than 3 weight percent.
 30. The polymeric composite of claim 28,wherein MgO is present in an amount greater than 6 weight percent, andthe additional feature comprises CaO in an amount less than 1.5 weightpercent.
 31. The polymeric composite of claim 28, wherein the additionalfeature comprises a SiO₂/Al₂O₃ ratio in an amount greater than 4.2. 32.The polymeric composite of claim 28, further comprising less than 1.5weight percent Na₂O+K₂O+Li₂O.
 33. An article of manufacture comprising:SiO₂ 51-65 weight percent; Al₂O₃ 12.5-19 weight percent; CaO 0-20 weightpercent; MgO 0-12 weight percent; Na₂O 0-2.5 weight percent; K₂O 0-1weight percent; TiO₂ 0-3 weight percent; B₂O₃ 0-3 weight percent; P₂O₅0-3 weight percent; Fe₂O₃ 0-1 weight percent;

Li₂O in an amount greater than 0 weight percent and up to 2 weightpercent; and at least one rare earth oxide is present in an amountgreater than 1 weight percent, wherein the article of manufacture issubstantially free of Y₂O₃, the MgO content is greater than four timesthe CaO content, or the CaO content is greater than the MgO content. 34.The article of manufacture of claim 33, wherein the article is a roving.35. The article of manufacture of claim 33, wherein the article is ayarn.
 36. The article of manufacture of claim 33, wherein the article isa fabric.
 37. The article of manufacture of claim 36, wherein the fabricis woven.
 38. The article of manufacture of claim 33, wherein thearticle is a composite.